diff --git a/main_v2.py b/main_v2.py
index 4986ee9..8242760 100644
--- a/main_v2.py
+++ b/main_v2.py
@@ -546,14 +546,20 @@ async def websocket_endpoint(websocket: WebSocket, user_id: str):
                     
                     if conversation:
                         messages = conv_service.get_messages(conversation.id)
+                        
+                        # 获取对话使用的Agent ID
+                        conv_agent_id = conversation.current_agent_id
+                        
                         await websocket.send_json({
                             "type": "history",
                             "conversation_id": current_conversation_id,
+                            "agent_id": conv_agent_id,  # 返回对话的Agent ID
                             "messages": [
                                 {
                                     "role": m.role,
                                     "content": m.content,
                                     "thinking_content": m.thinking_content,
+                                    "agent_id": m.agent_id,  # 每条消息的Agent ID
                                     "source": m.source,
                                     "created_at": m.created_at.isoformat()
                                 }
diff --git a/templates/index.html b/templates/index.html
index 56259fc..484cf39 100644
--- a/templates/index.html
+++ b/templates/index.html
@@ -192,10 +192,7 @@
                 const data = await res.json();
                 agents = data.agents || [];
                 
-                const select = document.getElementById('agentSelect');
-                select.innerHTML = agents.filter(a => a.is_active).map(a => 
-                    `<option value="${a.id}" ${a.is_default ? 'selected' : ''}>${a.display_name || a.name}</option>`
-                ).join('');
+                renderAgentSelect();
                 
                 // 设置当前Agent
                 const defaultAgent = agents.find(a => a.is_default) || agents[0];
@@ -206,6 +203,22 @@
             }
         }
         
+        // 渲染Agent下拉框
+        function renderAgentSelect(selectedId = null) {
+            const select = document.getElementById('agentSelect');
+            const selected = selectedId || currentAgentId;
+            select.innerHTML = agents.filter(a => a.is_active).map(a => 
+                `<option value="${a.id}" ${a.id === selected ? 'selected' : ''}>${a.display_name || a.name}</option>`
+            ).join('');
+        }
+        
+        // 更新Agent选择框显示
+        function updateAgentSelect(agentId) {
+            const select = document.getElementById('agentSelect');
+            select.value = agentId;
+            currentAgentId = agentId;
+        }
+        
         // 切换Agent - 自动创建新对话
         async function switchAgent() {
             const newAgentId = document.getElementById('agentSelect').value;
@@ -336,6 +349,11 @@
             switch (data.type) {
                 case 'history':
                     displayHistory(data.messages);
+                    // 更新Agent选择框为该对话使用的Agent
+                    if (data.agent_id) {
+                        currentAgentId = data.agent_id;
+                        updateAgentSelect(data.agent_id);
+                    }
                     break;
                 case 'conversation_created':
                     currentConversationId = data.conversation_id;