diff --git a/server/public/index.html b/server/public/index.html
index b0809f8..96d8dc8 100644
--- a/server/public/index.html
+++ b/server/public/index.html
@@ -192,7 +192,7 @@
         let currentRoom = null;
         let rooms = [];
         let pendingUploads = [];
-        const sentMsgIds = new Set();  // 已发送成功的消息 ID 集合，防止重复
+        const sentMsgIds = new Set(); // 本地已处理的消息 ID，防止广播重复
 
         function getToken() { return localStorage.getItem('token'); }
         function saveAuth(data) {
@@ -303,8 +303,7 @@
                 const data = JSON.parse(e.data);
                 if (data.type === 'new_message') {
                     const msg = data.message;
-                    // 去重：如果消息 ID 已在发送确认集合中，忽略广播
-                    if (sentMsgIds.has(msg.id)) return;
+                    // 发送者本人不会收到自己的广播（已由后端过滤），因此直接添加
                     if (currentRoom === msg.room_id) {
                         appendMessage(msg);
                     }
@@ -483,7 +482,7 @@
                     body: JSON.stringify({ text: text || '', attachments: pendingUploads })
                 });
                 const newMsg = await res.json();
-                sentMsgIds.add(newMsg.id);   // 记录已发送，避免广播重复
+                // 不记录 sentMsgIds，因为后端已经过滤，我们直接 append
                 appendMessage(newMsg);
                 input.value = '';
                 pendingUploads = [];
@@ -492,13 +491,12 @@
             }
         }
 
-        // 选图后自动压缩上传，然后调用 sendMessage，确保占位
+        // 选图后自动压缩上传，显示占位，然后发送
         async function handleFileSelect(event) {
             const files = event.target.files;
             if (!files.length) return;
 
             const token = getToken();
-            // 立即显示占位消息
             const placeholderId = 'placeholder_' + Date.now();
             const placeholderMsg = {
                 id: placeholderId,
@@ -529,11 +527,11 @@
                     const data = await res.json();
                     if (data.path) pendingUploads.push(data.path);
                 }
-                // 上传完毕，移除占位并发送正式消息
+                // 移除占位
                 window._messagesCache = window._messagesCache.filter(m => m.id !== placeholderId);
-                sendMessage();  // 会自动带上 pendingUploads
+                // 发送正式消息
+                sendMessage();
             } catch(e) {
-                // 失败则移除占位
                 window._messagesCache = window._messagesCache.filter(m => m.id !== placeholderId);
                 renderMessages(window._messagesCache);
                 alert('图片发送失败，请重试');
diff --git a/server/server.js b/server/server.js
index 8eda128..a87205c 100644
--- a/server/server.js
+++ b/server/server.js
@@ -42,7 +42,7 @@ const storage = multer.diskStorage({
 });
 const upload = multer({
   storage,
-  limits: { fileSize: 5 * 1024 * 1024 }, // 5MB
+  limits: { fileSize: 5 * 1024 * 1024 },
   fileFilter: (req, file, cb) => {
     const allowed = ['image/jpeg','image/png','image/gif'];
     cb(null, allowed.includes(file.mimetype));
@@ -80,7 +80,6 @@ app.get('/api/user', auth, (req, res) => {
   res.json({ username: req.user.username, isAdmin: req.user.isAdmin });
 });
 
-// 群聊列表（带最后消息）
 app.get('/api/rooms', auth, (req, res) => {
   const rooms = db.prepare('SELECT * FROM rooms').all();
   const result = rooms.map(room => {
@@ -126,19 +125,26 @@ app.post('/api/rooms/:roomId/messages', auth, (req, res) => {
     attachments: attachments || [],
     timestamp
   };
+
   // 房间最后消息预览
   const lastMsg = db.prepare('SELECT text, timestamp FROM messages WHERE room_id = ? ORDER BY timestamp DESC LIMIT 1').get(roomId);
-  broadcastToRoom(roomId, {
+  const preview = {
+    room_id: roomId,
+    last_message: lastMsg ? lastMsg.text : '',
+    last_time: lastMsg ? lastMsg.timestamp : ''
+  };
+
+  // 广播给房间内其他成员，但不包括发送者自己
+  broadcastToRoomExcludeSelf(roomId, username, {
     type: 'new_message',
     message: msg,
-    room_preview: {
-      room_id: roomId,
-      last_message: lastMsg ? lastMsg.text : '',
-      last_time: lastMsg ? lastMsg.timestamp : ''
-    }
+    room_preview: preview
   });
+
   // 加入对话历史
   addToHistory(roomId, 'user', `${username}: ${text || '图片'}`);
+
+  // 返回消息给发送者
   res.json(msg);
 });
 
@@ -186,7 +192,8 @@ app.get('/api/rooms/:roomId/purchases/export', auth, (req, res) => {
 });
 
 // WebSocket 管理
-const clients = new Map();
+const clients = new Map(); // ws -> { username, roomId }
+
 wss.on('connection', (ws, req) => {
   console.log('✅ WebSocket 客户端已连接');
   const url = new URL(req.url, 'http://localhost');
@@ -220,6 +227,17 @@ wss.on('connection', (ws, req) => {
   });
 });
 
+// 广播给房间内所有成员，排除指定用户
+function broadcastToRoomExcludeSelf(roomId, excludeUsername, data) {
+  const message = JSON.stringify(data);
+  clients.forEach((info, ws) => {
+    if (info.roomId === roomId && info.username !== excludeUsername && ws.readyState === 1) {
+      ws.send(message);
+    }
+  });
+}
+
+// 广播给房间内所有人
 function broadcastToRoom(roomId, data) {
   const message = JSON.stringify(data);
   clients.forEach((info, ws) => {
@@ -229,6 +247,7 @@ function broadcastToRoom(roomId, data) {
   });
 }
 
+// 全局广播
 function broadcast(data) {
   const message = JSON.stringify(data);
   clients.forEach((ws) => {
@@ -236,7 +255,7 @@ function broadcast(data) {
   });
 }
 
-// 文本消息存储并广播（用于 AI 回复等内部消息）
+// 内部消息存储并广播（用于 AI 回复等）
 function storeAndBroadcastText(roomId, user, text) {
   const timestamp = new Date().toLocaleString('zh-CN', { hour12: false });
   const result = db.prepare('INSERT INTO messages (room_id, user, text, timestamp) VALUES (?,?,?,?)').run(roomId, user, text, timestamp);
@@ -266,7 +285,7 @@ function addToHistory(roomId, role, content) {
   if (history.length > 60) conversationHistory.set(roomId, history.slice(-40));
 }
 
-// AI 处理相关函数（保持不变）
+// AI 处理（保持原逻辑）
 async function analyzeWithDeepSeek(text, historyMessages, username) {
   const systemPrompt = `你是智能财务助手“小财”。结合对话历史理解用户意图。只返回JSON。