diff --git a/src/api/chat.ts b/src/api/chat.ts
index 66eb5dc..2dfba33 100644
--- a/src/api/chat.ts
+++ b/src/api/chat.ts
@@ -13,6 +13,14 @@ export interface ToolCallTrace {
   result: any;
 }
 
+export interface ModelOverrides {
+  model?: string;
+  model_id?: string;
+  temperature?: number;
+  topP?: number;
+  maxTokens?: number;
+}
+
 export interface ChatMessage {
   id: string;
   role: 'user' | 'assistant' | 'agent' | 'system';
@@ -48,13 +56,12 @@ export interface ChatHistoryResp {
 export const ChatAPI = {
   history: (roomId: string) =>
     api.get<ChatHistoryResp>(`/rooms/${roomId}/messages`).then((r) => r.data),
-  send: (roomId: string, content: string, targetAgentId: string, model?: string, model_id?: string, imageUrls?: string[]) =>
+  send: (roomId: string, content: string, targetAgentId: string, overrides?: ModelOverrides, imageUrls?: string[]) =>
     api
       .post<{ user: ChatMessage; assistant: ChatMessage }>(`/rooms/${roomId}/messages`, {
         content,
         targetAgentId,
-        model,
-        model_id,
+        ...overrides,
         imageUrls
       })
       .then((r) => r.data),
diff --git a/src/api/streamChat.ts b/src/api/streamChat.ts
index 1bcfc57..600b0f7 100644
--- a/src/api/streamChat.ts
+++ b/src/api/streamChat.ts
@@ -1,4 +1,4 @@
-import type { ChatMessage } from './chat';
+import type { ChatMessage, ModelOverrides } from './chat';
 import { API_BASE_URL } from './http';
 
 export interface StreamEvents {
@@ -13,22 +13,13 @@ export interface StreamEvents {
   onError?: (msg: string) => void;
 }
 
-export interface ModelOverrides {
-  model?: string;
-  model_id?: string;
-  temperature?: number;
-  topP?: number;
-  maxTokens?: number;
-}
-
 export async function streamChat(
   roomId: string,
   targetAgentId: string,
   content: string,
   handlers: StreamEvents,
   signal?: AbortSignal,
-  model?: string,
-  modelId?: string,
+  overrides?: ModelOverrides,
   imageUrls?: string[]
 ) {
   const resp = await fetch(`${API_BASE_URL}rooms/${roomId}/messages/stream`, {
@@ -37,8 +28,7 @@ export async function streamChat(
     body: JSON.stringify({
       content,
       targetAgentId,
-      model,
-      model_id: modelId,
+      ...overrides,
       imageUrls: imageUrls ?? []
     }),
     signal,
@@ -47,24 +37,6 @@ export async function streamChat(
   return await consumeSSE(resp, handlers, signal);
 }
 
-export async function regenerateMessage(
-  agentId: string,
-  messageId: string,
-  handlers: StreamEvents,
-  signal?: AbortSignal,
-  overrides?: ModelOverrides,
-  attachmentsText?: string
-) {
-  const resp = await fetch(`${API_BASE_URL}chat/${agentId}/messages/${messageId}/regenerate`, {
-    method: 'POST',
-    headers: { 'Content-Type': 'application/json', Accept: 'text/event-stream' },
-    body: JSON.stringify({ overrides, attachmentsText }),
-    signal,
-    credentials: 'include'
-  });
-  return await consumeSSE(resp, handlers, signal);
-}
-
 async function consumeSSE(resp: Response, h: StreamEvents, signal?: AbortSignal) {
   if (!resp.ok || !resp.body) {
     const txt = await resp.text().catch(() => '');
@@ -150,4 +122,3 @@ async function consumeSSE(resp: Response, h: StreamEvents, signal?: AbortSignal)
     reader.cancel().catch(() => {});
   }
 }
-
diff --git a/src/components/ChatPreview.tsx b/src/components/ChatPreview.tsx
index ab0d05b..bace61c 100644
--- a/src/components/ChatPreview.tsx
+++ b/src/components/ChatPreview.tsx
@@ -107,7 +107,7 @@ export default function ChatPreview({ agent, agentId }: Props) {
             }),
           onDone: (data) => {
             setMessages((m) => [...m.filter((x) => x.id !== tempUser.id), data.user, data.assistant]);
-           setStreaming({ active: false, text: '', retrieved: [], toolCalls: [] });
+            setStreaming({ active: false, text: '', retrieved: [], toolCalls: [] });
             scrollBottom();
           },
           onError: (errMsg) => {
@@ -117,8 +117,7 @@ export default function ChatPreview({ agent, agentId }: Props) {
           }
         },
         ctrl.signal,
-        model,
-        modelId
+        { model, model_id: modelId }
       );
     } catch (e: any) {
       if (e?.name !== 'AbortError') {
diff --git a/src/pages/chat/components/messages/MessageItem.tsx b/src/pages/chat/components/messages/MessageItem.tsx
index 1619f63..bae761b 100644
--- a/src/pages/chat/components/messages/MessageItem.tsx
+++ b/src/pages/chat/components/messages/MessageItem.tsx
@@ -95,7 +95,7 @@ export default function MessageItem(props: {
                     <Button size="small" className='actions-btn' type="text" icon={<CopyOutlined />} />
                   </Tooltip>
                 </Dropdown>
-                <Tooltip title="重新生成（开新分支）">
+                <Tooltip title="重新生成">
                   <Button size="small" className='actions-btn' type="text" icon={<SyncOutlined />} disabled={busy} onClick={() => onRegenerate?.(message.id)} />
                 </Tooltip>
               </div>
diff --git a/src/pages/chat/hooks/useChatSender.ts b/src/pages/chat/hooks/useChatSender.ts
index 565d714..a1c0d4d 100644
--- a/src/pages/chat/hooks/useChatSender.ts
+++ b/src/pages/chat/hooks/useChatSender.ts
@@ -1,6 +1,6 @@
 import { useMemo, useState } from 'react';
 import type { Agent, BranchInfo, ChatAttachment, ChatMessage, ModelOverrides, RetrievedSnippet, ToolCallTrace } from '../../../api';
-import { ChatAPI, ChatAttachmentsAPI, ImageAPI, regenerateMessage, streamChat } from '../../../api';
+import { ChatAPI, ChatAttachmentsAPI, ImageAPI, streamChat } from '../../../api';
 import { buildAttachmentsText } from '../utils/attachments';
 import { parseAgentModels } from '../utils/agentModels';
 
@@ -235,8 +235,7 @@ export function useChatSender(args: {
           }
         },
         ctrl.signal,
-        targetModel,
-        targetModelId,
+        { ...overrides, model: targetModel, model_id: targetModelId },
         imageUrls
       );
     } catch (e: any) {
@@ -284,7 +283,7 @@ export function useChatSender(args: {
     const attText = buildAttachmentsText(attachments);
     const content = attText ? `${text}\n\n${attText}` : text;
     try {
-      const res = await ChatAPI.send(roomId, content, targetAgentId, targetModel, targetModelId, imageUrls);
+      const res = await ChatAPI.send(roomId, content, targetAgentId, { ...overrides, model: targetModel, model_id: targetModelId }, imageUrls);
       args.setMessages((m) => [...(m || []).filter((x) => x.id !== tempUser.id), res.user, res.assistant]);
       setSessionRefresh((t) => t + 1);
       setAttachments([]);
@@ -327,65 +326,25 @@ export function useChatSender(args: {
   };
 
   const handleRegenerate = async (assistantId: string) => {
-    if (!agentId || sending) return;
+    if (!agentId || sending || !roomId) return;
+
+    // 找到当前要重新生成的助手消息，并回溯找到它的父消息（用户消息）
+    const assistantMsg = args.messages.find((m) => m.id === assistantId);
+    const userMsgId = assistantMsg?.parentId;
+    const userMsg = args.messages.find((m) => m.id === userMsgId);
+
+    // 如果找不到父消息，则尝试找最后一条用户消息
+    const lastUserMsg = [...args.messages].reverse().find((m) => m.role === 'user');
+    const targetUserMsg = userMsg || lastUserMsg;
+
+    if (!targetUserMsg) {
+      notify.error('找不到上一条用户消息');
+      return;
+    }
+
     setSending(true);
-    setStreaming({ active: true, reasoningText: '', answerText: '', errorMessage: null, retryInfo: null, retrieved: [], toolCalls: [] });
-    abortRef.current?.abort();
-    const ctrl = new AbortController();
-    abortRef.current = ctrl;
     try {
-      await regenerateMessage(
-        agentId,
-        assistantId,
-        {
-          onMeta: (m) => setStreaming((s) => ({ ...s, retrieved: m.retrieved || [] })),
-          onRetry: (data) => {
-            setStreaming((s) => ({ ...s, retryInfo: data }));
-            if (data?.stage === 'fallback_model' && data?.toModel) {
-              setOverrides((o) => ({ ...o, model: String(data.toModel) }));
-            }
-          },
-          onReasoningDelta: (chunk) =>
-            setStreaming((s) => {
-              const next = { ...s, reasoningText: s.reasoningText + chunk };
-              scrollBottom();
-              return next;
-            }),
-          onDelta: (chunk) =>
-            setStreaming((s) => {
-              const next = { ...s, answerText: s.answerText + chunk };
-              scrollBottom();
-              return next;
-            }),
-          onToolCall: (data) => setStreaming((s) => ({ ...s, toolCalls: [...s.toolCalls, { name: data.name, args: data.args, result: { pending: true } }] })),
-          onToolResult: (data) =>
-            setStreaming((s) => {
-              const list = [...s.toolCalls];
-              for (let i = list.length - 1; i >= 0; i--) {
-                if (list[i].name === data.name && (list[i].result as any)?.pending) {
-                  list[i] = { ...list[i], result: data.result };
-                  break;
-                }
-              }
-              return { ...s, toolCalls: list };
-            }),
-          onDone: () => {
-            setStreaming({ active: false, reasoningText: '', answerText: '', errorMessage: null, retryInfo: null, retrieved: [], toolCalls: [] });
-            loadMessages();
-          },
-          onAborted: () => {
-            setStreaming({ active: false, reasoningText: '', answerText: '', errorMessage: null, retryInfo: null, retrieved: [], toolCalls: [] });
-            loadMessages();
-          },
-          onError: (errMsg) => {
-            notify.error('重新生成失败：' + errMsg);
-            setStreaming({ active: false, reasoningText: '', answerText: '', errorMessage: errMsg, retryInfo: null, retrieved: [], toolCalls: [] });
-            loadMessages();
-          }
-        },
-        ctrl.signal,
-        overrides
-      );
+      await handleSendStream(targetUserMsg.content);
     } finally {
       setSending(false);
     }