diff --git a/backend/src/main/java/com/imeeting/websocket/RealtimeMeetingProxyWebSocketHandler.java b/backend/src/main/java/com/imeeting/websocket/RealtimeMeetingProxyWebSocketHandler.java
index 1d50161..2365b8f 100644
--- a/backend/src/main/java/com/imeeting/websocket/RealtimeMeetingProxyWebSocketHandler.java
+++ b/backend/src/main/java/com/imeeting/websocket/RealtimeMeetingProxyWebSocketHandler.java
@@ -22,7 +22,9 @@ import java.nio.charset.StandardCharsets;
 import java.time.Duration;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.function.Supplier;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.CompletionException;
@@ -81,10 +83,12 @@ public class RealtimeMeetingProxyWebSocketHandler extends AbstractWebSocketHandl
             Thread.currentThread().interrupt();
             log.error("Realtime websocket upstream connect interrupted: meetingId={}, sessionId={}",
                     sessionData.getMeetingId(), session.getId(), ex);
+            sendFrontendError(frontendSession, "REALTIME_UPSTREAM_CONNECT_INTERRUPTED", "连接第三方识别服务时被中断");
             frontendSession.close(CloseStatus.SERVER_ERROR.withReason("Interrupted while connecting upstream"));
             return;
         } catch (ExecutionException | CompletionException ex) {
             log.warn("Failed to connect upstream websocket, meetingId={}, target={}", sessionData.getMeetingId(), sessionData.getTargetWsUrl(), ex);
+            sendFrontendError(frontendSession, "REALTIME_UPSTREAM_CONNECT_FAILED", "连接第三方识别服务失败，请检查模型 WebSocket 配置或服务状态");
             frontendSession.close(CloseStatus.SERVER_ERROR.withReason("Failed to connect ASR websocket"));
             return;
         }
@@ -253,6 +257,21 @@ public class RealtimeMeetingProxyWebSocketHandler extends AbstractWebSocketHandl
         return normalized.contains("\"type\":\"start\"");
     }
 
+    private void sendFrontendError(ConcurrentWebSocketSessionDecorator frontendSession, String code, String message) {
+        try {
+            if (!frontendSession.isOpen()) {
+                return;
+            }
+            Map<String, Object> payload = new HashMap<>();
+            payload.put("type", "error");
+            payload.put("code", code);
+            payload.put("message", message);
+            frontendSession.sendMessage(new TextMessage(new com.fasterxml.jackson.databind.ObjectMapper().writeValueAsString(payload)));
+        } catch (Exception ex) {
+            log.warn("Failed to send realtime proxy error to frontend: code={}", code, ex);
+        }
+    }
+
     @SuppressWarnings("unchecked")
     private void queuePendingAudioFrame(WebSocketSession session, byte[] payload) {
         synchronized (session) {
@@ -304,6 +323,15 @@ public class RealtimeMeetingProxyWebSocketHandler extends AbstractWebSocketHandl
         public void onOpen(java.net.http.WebSocket webSocket) {
             log.info("Upstream websocket opened: meetingId={}, sessionId={}, upstream={}",
                     meetingId, rawSession.getId(), targetWsUrl);
+            try {
+                if (frontendSession.isOpen()) {
+                    frontendSession.sendMessage(new TextMessage("{\"type\":\"proxy_ready\"}"));
+                }
+            } catch (Exception ex) {
+                log.error("Failed to notify frontend that upstream websocket is ready: meetingId={}, sessionId={}", meetingId, rawSession.getId(), ex);
+                closeFrontend(CloseStatus.SERVER_ERROR);
+                return;
+            }
             webSocket.request(1);
         }
 
@@ -391,6 +419,7 @@ public class RealtimeMeetingProxyWebSocketHandler extends AbstractWebSocketHandl
         public java.util.concurrent.CompletionStage<?> onClose(java.net.http.WebSocket webSocket, int statusCode, String reason) {
             log.info("Upstream websocket closed: meetingId={}, sessionId={}, code={}, reason={}",
                     meetingId, rawSession.getId(), statusCode, reason);
+            sendFrontendError("REALTIME_UPSTREAM_CLOSED", reason == null || reason.isBlank() ? "第三方识别服务已断开连接" : "第三方识别服务已断开: " + reason);
             closeFrontend(new CloseStatus(statusCode, reason));
             return COMPLETED;
         }
@@ -399,9 +428,34 @@ public class RealtimeMeetingProxyWebSocketHandler extends AbstractWebSocketHandl
         public void onError(java.net.http.WebSocket webSocket, Throwable error) {
             log.error("Upstream websocket error: meetingId={}, sessionId={}, upstream={}",
                     meetingId, rawSession.getId(), targetWsUrl, error);
+            sendFrontendError("REALTIME_UPSTREAM_ERROR", error == null || error.getMessage() == null || error.getMessage().isBlank()
+                    ? "第三方识别服务连接异常"
+                    : "第三方识别服务连接异常: " + error.getMessage());
             closeFrontend(CloseStatus.SERVER_ERROR);
         }
 
+        private void sendFrontendError(String code, String message) {
+            try {
+                if (!frontendSession.isOpen()) {
+                    return;
+                }
+                frontendSession.sendMessage(new TextMessage("{\"type\":\"error\",\"code\":\"" + code + "\",\"message\":\"" + escapeJson(message) + "\"}"));
+            } catch (Exception ex) {
+                log.warn("Failed to send upstream error to frontend: meetingId={}, sessionId={}, code={}", meetingId, rawSession.getId(), code, ex);
+            }
+        }
+
+        private String escapeJson(String value) {
+            if (value == null) {
+                return "";
+            }
+            return value
+                    .replace("\\", "\\\\")
+                    .replace("\"", "\\\"")
+                    .replace("\r", "\\r")
+                    .replace("\n", "\\n");
+        }
+
         private void closeFrontend(CloseStatus status) {
             try {
                 if (rawSession.isOpen()) {
diff --git a/frontend/src/pages/business/RealtimeAsrSession.tsx b/frontend/src/pages/business/RealtimeAsrSession.tsx
index 973db7b..cabc4d3 100644
--- a/frontend/src/pages/business/RealtimeAsrSession.tsx
+++ b/frontend/src/pages/business/RealtimeAsrSession.tsx
@@ -45,7 +45,7 @@ const CHUNK_SIZE = 1280;
 type WsSpeaker = string | { name?: string; user_id?: string | number } | undefined;
 type WsMessage = {
   type?: string;
-  code?: number;
+  code?: number | string;
   message?: string;
   data?: {
     text?: string;
@@ -203,6 +203,7 @@ export default function RealtimeAsrSession() {
   const audioBufferRef = useRef<number[]>([]);
   const completeOnceRef = useRef(false);
   const startedAtRef = useRef<number | null>(null);
+  const sessionStartedRef = useRef(false);
 
   const finalTranscriptCount = transcripts.length;
   const totalTranscriptChars = useMemo(
@@ -306,6 +307,18 @@ export default function RealtimeAsrSession() {
     setAudioLevel(0);
   };
 
+  const handleFatalRealtimeError = async (errorMessage: string) => {
+    setConnecting(false);
+    setRecording(false);
+    setStatusText("连接失败");
+    sessionStartedRef.current = false;
+    wsRef.current?.close();
+    wsRef.current = null;
+    await shutdownAudioPipeline();
+    startedAtRef.current = null;
+    message.error(errorMessage);
+  };
+
   const startAudioPipeline = async () => {
     if (!window.isSecureContext || !navigator.mediaDevices?.getUserMedia) {
       throw new Error("当前浏览器环境不支持麦克风访问。请使用 localhost 或 HTTPS 域名访问系统。");
@@ -384,6 +397,7 @@ export default function RealtimeAsrSession() {
 
     setConnecting(true);
     setStatusText("连接识别服务...");
+    sessionStartedRef.current = false;
     try {
       const socketSessionRes = await openRealtimeMeetingSocketSession(meetingId, {
         asrModelId: sessionDraft.asrModelId,
@@ -401,21 +415,36 @@ export default function RealtimeAsrSession() {
       socket.binaryType = "arraybuffer";
       wsRef.current = socket;
 
-      socket.onopen = async () => {
-        socket.send(JSON.stringify(socketSession.startMessage || {}));
-        await startAudioPipeline();
-        startedAtRef.current = Date.now();
-        setConnecting(false);
-        setRecording(true);
-        setStatusText("实时识别中");
+      socket.onopen = () => {
+        setStatusText("识别服务连接中，等待第三方服务就绪...");
       };
 
       socket.onmessage = (event) => {
         try {
           const payload = JSON.parse(event.data) as WsMessage;
-          if (payload.code && payload.message) {
+          if (payload.type === "proxy_ready") {
+            if (sessionStartedRef.current) {
+              return;
+            }
+            sessionStartedRef.current = true;
+            setStatusText("启动音频采集中...");
+            socket.send(JSON.stringify(socketSession.startMessage || {}));
+            void startAudioPipeline()
+              .then(() => {
+                startedAtRef.current = Date.now();
+                setConnecting(false);
+                setRecording(true);
+                setStatusText("实时识别中");
+              })
+              .catch((error) => {
+                void handleFatalRealtimeError(error instanceof Error ? error.message : "启动麦克风失败");
+              });
+            return;
+          }
+
+          if ((payload.code || payload.type === "error") && payload.message) {
             setStatusText(payload.message);
-            message.error(payload.message);
+            void handleFatalRealtimeError(payload.message);
             return;
           }
 
@@ -451,19 +480,18 @@ export default function RealtimeAsrSession() {
       };
 
       socket.onerror = () => {
-        setConnecting(false);
-        setRecording(false);
-        setStatusText("连接失败");
-        message.error("实时识别 WebSocket 连接失败");
+        void handleFatalRealtimeError("实时识别 WebSocket 连接失败");
       };
 
       socket.onclose = () => {
         setConnecting(false);
         setRecording(false);
+        sessionStartedRef.current = false;
       };
     } catch (error) {
       setConnecting(false);
       setStatusText("启动失败");
+      sessionStartedRef.current = false;
       message.error(error instanceof Error ? error.message : "启动实时识别失败");
     }
   };
@@ -482,6 +510,7 @@ export default function RealtimeAsrSession() {
     }
     wsRef.current?.close();
     wsRef.current = null;
+    sessionStartedRef.current = false;
 
     await shutdownAudioPipeline();
 
@@ -500,6 +529,7 @@ export default function RealtimeAsrSession() {
       setRecording(false);
       setFinishing(false);
       startedAtRef.current = null;
+      sessionStartedRef.current = false;
     }
   };