diff --git a/docSite/content/zh-cn/docs/development/upgrading/4820.md b/docSite/content/zh-cn/docs/development/upgrading/4820.md
index 07f86b464..ecf160a9b 100644
--- a/docSite/content/zh-cn/docs/development/upgrading/4820.md
+++ b/docSite/content/zh-cn/docs/development/upgrading/4820.md
@@ -35,4 +35,5 @@ curl --location --request POST 'https://{{host}}/api/admin/initv4820' \
 3. 新增 - markdown 语法扩展，支持音视频（代码块 audio 和 video）。
 4. 优化 - 页面组件抽离，减少页面组件路由。
 5. 优化 - 全文检索，忽略大小写。
-6. 优化 - 问答生成和增强索引改成流输出，避免部分模型超时。
\ No newline at end of file
+6. 优化 - 问答生成和增强索引改成流输出，避免部分模型超时。
+7. 优化 - 自动给 assistant 空 content，补充 null，同时合并连续的 text assistant，避免部分模型抛错。
\ No newline at end of file
diff --git a/packages/service/core/chat/utils.ts b/packages/service/core/chat/utils.ts
index ed35466e8..130b894e8 100644
--- a/packages/service/core/chat/utils.ts
+++ b/packages/service/core/chat/utils.ts
@@ -1,6 +1,9 @@
 import { countGptMessagesTokens } from '../../common/string/tiktoken/index';
 import type {
+  ChatCompletionAssistantMessageParam,
   ChatCompletionContentPart,
+  ChatCompletionContentPartRefusal,
+  ChatCompletionContentPartText,
   ChatCompletionMessageParam,
   SdkChatCompletionMessageParam
 } from '@fastgpt/global/core/ai/type.d';
@@ -102,223 +105,324 @@ export const loadRequestMessages = async ({
   useVision?: boolean;
   origin?: string;
 }) => {
-  // Load image to base64
-  const loadImageToBase64 = async (messages: ChatCompletionContentPart[]) => {
-    return Promise.all(
-      messages.map(async (item) => {
-        if (item.type === 'image_url') {
-          // Remove url origin
-          const imgUrl = (() => {
-            if (origin && item.image_url.url.startsWith(origin)) {
-              return item.image_url.url.replace(origin, '');
-            }
-            return item.image_url.url;
-          })();
-
-          // base64 image
-          if (imgUrl.startsWith('data:image/')) {
-            return item;
-          }
-
-          try {
-            // If imgUrl is a local path, load image from local, and set url to base64
-            if (imgUrl.startsWith('/') || process.env.MULTIPLE_DATA_TO_BASE64 === 'true') {
-              addLog.debug('Load image from local server', {
-                baseUrl: serverRequestBaseUrl,
-                requestUrl: imgUrl
-              });
-              const response = await axios.get(imgUrl, {
-                baseURL: serverRequestBaseUrl,
-                responseType: 'arraybuffer',
-                proxy: false
-              });
-              const base64 = Buffer.from(response.data, 'binary').toString('base64');
-              const imageType =
-                getFileContentTypeFromHeader(response.headers['content-type']) ||
-                guessBase64ImageType(base64);
-
-              return {
-                ...item,
-                image_url: {
-                  ...item.image_url,
-                  url: `data:${imageType};base64,${base64}`
-                }
-              };
-            }
-
-            // 检查下这个图片是否可以被访问，如果不行的话，则过滤掉
-            const response = await axios.head(imgUrl, {
-              timeout: 10000
-            });
-            if (response.status < 200 || response.status >= 400) {
-              addLog.info(`Filter invalid image: ${imgUrl}`);
-              return;
-            }
-          } catch (error) {
-            return;
-          }
-        }
-        return item;
-      })
-    ).then((res) => res.filter(Boolean) as ChatCompletionContentPart[]);
+  const replaceLinkUrl = (text: string) => {
+    const baseURL = process.env.FE_DOMAIN;
+    if (!baseURL) return text;
+    // 匹配 /api/system/img/xxx.xx 的图片链接，并追加 baseURL
+    return text.replace(/(\/api\/system\/img\/[^\s.]*\.[^\s]*)/g, (match, p1) => `${baseURL}${p1}`);
   };
-  // Split question text and image
-  const parseStringWithImages = (input: string): ChatCompletionContentPart[] => {
-    if (!useVision || input.length > 500) {
-      return [{ type: 'text', text: input || '' }];
+  const parseSystemMessage = (
+    content: string | ChatCompletionContentPartText[]
+  ): string | ChatCompletionContentPartText[] | undefined => {
+    if (typeof content === 'string') {
+      if (!content) return;
+      return replaceLinkUrl(content);
     }
 
-    // 正则表达式匹配图片URL
-    const imageRegex =
-      /(https?:\/\/[^\s/$.?#].[^\s]*\.(?:png|jpe?g|gif|webp|bmp|tiff?|svg|ico|heic|avif))/gi;
-
-    const result: ChatCompletionContentPart[] = [];
-
-    // 提取所有HTTPS图片URL并添加到result开头
-    const httpsImages = [...new Set(Array.from(input.matchAll(imageRegex), (m) => m[0]))];
-    httpsImages.forEach((url) => {
-      result.push({
-        type: 'image_url',
-        image_url: {
-          url: url
-        }
-      });
-    });
-
-    // Too many images return text
-    if (httpsImages.length > 4) {
-      return [{ type: 'text', text: input || '' }];
-    }
-
-    // 添加原始input作为文本
-    result.push({ type: 'text', text: input });
-    return result;
+    const arrayContent = content
+      .filter((item) => item.text)
+      .map((item) => ({ ...item, text: replaceLinkUrl(item.text) }));
+    if (arrayContent.length === 0) return;
+    return arrayContent;
   };
   // Parse user content(text and img) Store history => api messages
   const parseUserContent = async (content: string | ChatCompletionContentPart[]) => {
-    if (typeof content === 'string') {
-      return loadImageToBase64(parseStringWithImages(content));
-    }
-
-    const result = await Promise.all(
-      content.map(async (item) => {
-        if (item.type === 'text') return parseStringWithImages(item.text);
-        if (item.type === 'file_url') return; // LLM not support file_url
-
-        if (!item.image_url.url) return item;
-
-        return item;
-      })
-    );
-
-    return loadImageToBase64(result.flat().filter(Boolean) as ChatCompletionContentPart[]);
-  };
-
-  // format GPT messages, concat text messages
-  const clearInvalidMessages = (messages: ChatCompletionMessageParam[]) => {
-    return messages
-      .map((item) => {
-        if (item.role === ChatCompletionRequestMessageRoleEnum.System && !item.content) {
-          return;
-        }
-        if (item.role === ChatCompletionRequestMessageRoleEnum.User) {
-          if (item.content === undefined) return;
-
-          if (typeof item.content === 'string') {
-            return {
-              ...item,
-              content: item.content.trim()
-            };
-          }
-
-          // array
-          if (item.content.length === 0) return;
-          if (item.content.length === 1 && item.content[0].type === 'text') {
-            return {
-              ...item,
-              content: item.content[0].text
-            };
-          }
-        }
-        if (item.role === ChatCompletionRequestMessageRoleEnum.Assistant) {
-          if (item.content === undefined && !item.tool_calls && !item.function_call) return;
-        }
-
-        return item;
-      })
-      .filter(Boolean) as ChatCompletionMessageParam[];
-  };
-  /* 
-    Merge data for some consecutive roles
-    1. Contiguous assistant and both have content, merge content
-  */
-  const mergeConsecutiveMessages = (
-    messages: ChatCompletionMessageParam[]
-  ): ChatCompletionMessageParam[] => {
-    return messages.reduce((mergedMessages: ChatCompletionMessageParam[], currentMessage) => {
-      const lastMessage = mergedMessages[mergedMessages.length - 1];
-
-      if (
-        lastMessage &&
-        currentMessage.role === ChatCompletionRequestMessageRoleEnum.Assistant &&
-        lastMessage.role === ChatCompletionRequestMessageRoleEnum.Assistant &&
-        typeof lastMessage.content === 'string' &&
-        typeof currentMessage.content === 'string'
-      ) {
-        lastMessage.content += currentMessage ? `\n${currentMessage.content}` : '';
-      } else {
-        mergedMessages.push(currentMessage);
+    // Split question text and image
+    const parseStringWithImages = (input: string): ChatCompletionContentPart[] => {
+      if (!useVision || input.length > 500) {
+        return [{ type: 'text', text: input }];
       }
 
-      return mergedMessages;
-    }, []);
+      // 正则表达式匹配图片URL
+      const imageRegex =
+        /(https?:\/\/[^\s/$.?#].[^\s]*\.(?:png|jpe?g|gif|webp|bmp|tiff?|svg|ico|heic|avif))/gi;
+
+      const result: ChatCompletionContentPart[] = [];
+
+      // 提取所有HTTPS图片URL并添加到result开头
+      const httpsImages = [...new Set(Array.from(input.matchAll(imageRegex), (m) => m[0]))];
+      httpsImages.forEach((url) => {
+        result.push({
+          type: 'image_url',
+          image_url: {
+            url: url
+          }
+        });
+      });
+
+      // Too many images return text
+      if (httpsImages.length > 4) {
+        return [{ type: 'text', text: input }];
+      }
+
+      // 添加原始input作为文本
+      result.push({ type: 'text', text: input });
+      return result;
+    };
+    // Load image to base64
+    const loadUserContentImage = async (content: ChatCompletionContentPart[]) => {
+      return Promise.all(
+        content.map(async (item) => {
+          if (item.type === 'image_url') {
+            // Remove url origin
+            const imgUrl = (() => {
+              if (origin && item.image_url.url.startsWith(origin)) {
+                return item.image_url.url.replace(origin, '');
+              }
+              return item.image_url.url;
+            })();
+
+            // base64 image
+            if (imgUrl.startsWith('data:image/')) {
+              return item;
+            }
+
+            try {
+              // If imgUrl is a local path, load image from local, and set url to base64
+              if (imgUrl.startsWith('/') || process.env.MULTIPLE_DATA_TO_BASE64 === 'true') {
+                addLog.debug('Load image from local server', {
+                  baseUrl: serverRequestBaseUrl,
+                  requestUrl: imgUrl
+                });
+                const response = await axios.get(imgUrl, {
+                  baseURL: serverRequestBaseUrl,
+                  responseType: 'arraybuffer',
+                  proxy: false
+                });
+                const base64 = Buffer.from(response.data, 'binary').toString('base64');
+                const imageType =
+                  getFileContentTypeFromHeader(response.headers['content-type']) ||
+                  guessBase64ImageType(base64);
+
+                return {
+                  ...item,
+                  image_url: {
+                    ...item.image_url,
+                    url: `data:${imageType};base64,${base64}`
+                  }
+                };
+              }
+
+              // 检查下这个图片是否可以被访问，如果不行的话，则过滤掉
+              const response = await axios.head(imgUrl, {
+                timeout: 10000
+              });
+              if (response.status < 200 || response.status >= 400) {
+                addLog.info(`Filter invalid image: ${imgUrl}`);
+                return;
+              }
+            } catch (error) {
+              return;
+            }
+          }
+          return item;
+        })
+      ).then((res) => res.filter(Boolean) as ChatCompletionContentPart[]);
+    };
+
+    if (content === undefined) return;
+    if (typeof content === 'string') {
+      if (content === '') return;
+
+      const loadImageContent = await loadUserContentImage(parseStringWithImages(content));
+      if (loadImageContent.length === 0) return;
+      return loadImageContent;
+    }
+
+    const result = (
+      await Promise.all(
+        content.map(async (item) => {
+          if (item.type === 'text') {
+            if (item.text) return parseStringWithImages(item.text);
+            return;
+          }
+          if (item.type === 'file_url') return; // LLM not support file_url
+          if (item.type === 'image_url') {
+            // close vision, remove image_url
+            if (!useVision) return;
+            // remove empty image_url
+            if (!item.image_url.url) return;
+          }
+
+          return item;
+        })
+      )
+    )
+      .flat()
+      .filter(Boolean) as ChatCompletionContentPart[];
+
+    const loadImageContent = await loadUserContentImage(result);
+
+    if (loadImageContent.length === 0) return;
+    return loadImageContent;
+  };
+
+  const formatAssistantItem = (item: ChatCompletionAssistantMessageParam) => {
+    return {
+      role: item.role,
+      content: item.content,
+      function_call: item.function_call,
+      name: item.name,
+      refusal: item.refusal,
+      tool_calls: item.tool_calls
+    };
+  };
+  const parseAssistantContent = (
+    content:
+      | string
+      | (ChatCompletionContentPartText | ChatCompletionContentPartRefusal)[]
+      | null
+      | undefined
+  ) => {
+    if (typeof content === 'string') {
+      return content || '';
+    }
+    // 交互节点
+    if (!content) return '';
+
+    const result = content.filter((item) => item?.type === 'text');
+    if (result.length === 0) return '';
+
+    return result.map((item) => item.text).join('\n');
   };
 
   if (messages.length === 0) {
     return Promise.reject(i18nT('common:core.chat.error.Messages empty'));
   }
 
-  // filter messages file
-  const filterMessages = messages.map((item) => {
-    // If useVision=false, only retain text.
-    if (
-      item.role === ChatCompletionRequestMessageRoleEnum.User &&
-      Array.isArray(item.content) &&
-      !useVision
-    ) {
-      return {
-        ...item,
-        content: item.content.filter((item) => item.type === 'text')
-      };
-    }
+  // 合并相邻 role 的内容，只保留一个 role， content 变成数组。 assistant 的话，工具调用不合并。
+  const mergeMessages = ((messages: ChatCompletionMessageParam[]): ChatCompletionMessageParam[] => {
+    return messages.reduce((mergedMessages: ChatCompletionMessageParam[], currentMessage) => {
+      const lastMessage = mergedMessages[mergedMessages.length - 1];
 
-    return item;
-  });
-
-  const loadMessages = (await Promise.all(
-    filterMessages.map(async (item) => {
-      if (item.role === ChatCompletionRequestMessageRoleEnum.User) {
-        return {
-          ...item,
-          content: await parseUserContent(item.content)
-        };
-      } else if (item.role === ChatCompletionRequestMessageRoleEnum.Assistant) {
-        // remove invalid field
-        return {
-          role: item.role,
-          content: item.content,
-          function_call: item.function_call,
-          name: item.name,
-          refusal: item.refusal,
-          tool_calls: item.tool_calls
-        };
-      } else {
-        return item;
+      if (!lastMessage) {
+        return [currentMessage];
       }
-    })
-  )) as ChatCompletionMessageParam[];
 
-  return mergeConsecutiveMessages(
-    clearInvalidMessages(loadMessages)
-  ) as SdkChatCompletionMessageParam[];
+      if (
+        lastMessage.role === ChatCompletionRequestMessageRoleEnum.System &&
+        currentMessage.role === ChatCompletionRequestMessageRoleEnum.System
+      ) {
+        const lastContent: ChatCompletionContentPartText[] = Array.isArray(lastMessage.content)
+          ? lastMessage.content
+          : [{ type: 'text', text: lastMessage.content || '' }];
+        const currentContent: ChatCompletionContentPartText[] = Array.isArray(
+          currentMessage.content
+        )
+          ? currentMessage.content
+          : [{ type: 'text', text: currentMessage.content || '' }];
+        lastMessage.content = [...lastContent, ...currentContent];
+      } // Handle user messages
+      else if (
+        lastMessage.role === ChatCompletionRequestMessageRoleEnum.User &&
+        currentMessage.role === ChatCompletionRequestMessageRoleEnum.User
+      ) {
+        const lastContent: ChatCompletionContentPart[] = Array.isArray(lastMessage.content)
+          ? lastMessage.content
+          : [{ type: 'text', text: lastMessage.content }];
+        const currentContent: ChatCompletionContentPart[] = Array.isArray(currentMessage.content)
+          ? currentMessage.content
+          : [{ type: 'text', text: currentMessage.content }];
+        lastMessage.content = [...lastContent, ...currentContent];
+      } else if (
+        lastMessage.role === ChatCompletionRequestMessageRoleEnum.Assistant &&
+        currentMessage.role === ChatCompletionRequestMessageRoleEnum.Assistant
+      ) {
+        // Content 不为空的对象，或者是交互节点
+        if (
+          (typeof lastMessage.content === 'string' ||
+            Array.isArray(lastMessage.content) ||
+            lastMessage.interactive) &&
+          (typeof currentMessage.content === 'string' ||
+            Array.isArray(currentMessage.content) ||
+            currentMessage.interactive)
+        ) {
+          const lastContent: (ChatCompletionContentPartText | ChatCompletionContentPartRefusal)[] =
+            Array.isArray(lastMessage.content)
+              ? lastMessage.content
+              : [{ type: 'text', text: lastMessage.content || '' }];
+          const currentContent: (
+            | ChatCompletionContentPartText
+            | ChatCompletionContentPartRefusal
+          )[] = Array.isArray(currentMessage.content)
+            ? currentMessage.content
+            : [{ type: 'text', text: currentMessage.content || '' }];
+
+          lastMessage.content = [...lastContent, ...currentContent];
+        } else {
+          // 有其中一个没有 content，说明不是连续的文本输出
+          mergedMessages.push(currentMessage);
+        }
+      } else {
+        mergedMessages.push(currentMessage);
+      }
+
+      return mergedMessages;
+    }, []);
+  })(messages);
+
+  const loadMessages = (
+    await Promise.all(
+      mergeMessages.map(async (item, i) => {
+        if (item.role === ChatCompletionRequestMessageRoleEnum.System) {
+          const content = parseSystemMessage(item.content);
+          if (!content) return;
+          return {
+            ...item,
+            content
+          };
+        } else if (item.role === ChatCompletionRequestMessageRoleEnum.User) {
+          const content = await parseUserContent(item.content);
+          if (!content) {
+            return {
+              ...item,
+              content: 'null'
+            };
+          }
+
+          const formatContent = (() => {
+            if (Array.isArray(content) && content.length === 1 && content[0].type === 'text') {
+              return content[0].text;
+            }
+            return content;
+          })();
+
+          return {
+            ...item,
+            content: formatContent
+          };
+        } else if (item.role === ChatCompletionRequestMessageRoleEnum.Assistant) {
+          if (item.tool_calls || item.function_call) {
+            return formatAssistantItem(item);
+          }
+
+          const parseContent = parseAssistantContent(item.content);
+
+          // 如果内容为空，且前后不再是 assistant，需要补充成 null，避免丢失 user-assistant 的交互
+          const formatContent = (() => {
+            const lastItem = mergeMessages[i - 1];
+            const nextItem = mergeMessages[i + 1];
+            if (
+              parseContent === '' &&
+              (lastItem?.role === ChatCompletionRequestMessageRoleEnum.Assistant ||
+                nextItem?.role === ChatCompletionRequestMessageRoleEnum.Assistant)
+            ) {
+              return;
+            }
+            return parseContent || 'null';
+          })();
+          if (!formatContent) return;
+
+          return {
+            ...formatAssistantItem(item),
+            content: formatContent
+          };
+        } else {
+          return item;
+        }
+      })
+    )
+  ).filter(Boolean) as ChatCompletionMessageParam[];
+
+  return loadMessages as SdkChatCompletionMessageParam[];
 };
diff --git a/packages/service/core/workflow/dispatch/agent/runTool/toolChoice.ts b/packages/service/core/workflow/dispatch/agent/runTool/toolChoice.ts
index 71d5f4021..2b0f7d457 100644
--- a/packages/service/core/workflow/dispatch/agent/runTool/toolChoice.ts
+++ b/packages/service/core/workflow/dispatch/agent/runTool/toolChoice.ts
@@ -272,7 +272,7 @@ export const runToolWithToolChoice = async (
     },
     toolModel
   );
-  // console.log(JSON.stringify(requestBody, null, 2), '==requestBody');
+  // console.log(JSON.stringify(requestMessages, null, 2), '==requestBody');
   /* Run llm */
   const {
     response: aiResponse,