diff --git a/main.c b/main.c
index cdb9cb8..5222739 100644
--- a/main.c
+++ b/main.c
@@ -1842,7 +1842,7 @@ void mqtt_init(){
     mqtt_config.tracelevel=MQTTASYNC_TRACE_PROTOCOL;
     mqtt_config.retain=0;
     mqtt_config.port=mqtt_port;
-    mqtt_config.keepalive=300;
+    mqtt_config.keepalive=180;
 
     memset(mqtt_config.clientid,0,sizeof(mqtt_config.clientid));
     memcpy(mqtt_config.clientid, clientid, strlen(clientid)+1);
diff --git a/mqtt/MQTTAsync.c b/mqtt/MQTTAsync.c
index a5813b4..dfdac17 100644
--- a/mqtt/MQTTAsync.c
+++ b/mqtt/MQTTAsync.c
@@ -2722,8 +2722,8 @@ static void setRetryLoopInterval(int keepalive)
 
 	if (proposed < 1)
 		proposed = 1;
-	else if (proposed > 5)
-		proposed = 5;
+	else if (proposed > 60)
+		proposed = 60;  // 提高上限到60秒，适应更长的keepalive
 	if (proposed < retryLoopInterval)
 		retryLoopInterval = proposed;
 }
diff --git a/mqtt/MQTTClient.c b/mqtt/MQTTClient.c
index 2069ff9..a058143 100644
--- a/mqtt/MQTTClient.c
+++ b/mqtt/MQTTClient.c
@@ -1323,8 +1323,8 @@ static void setRetryLoopInterval(int keepalive)
 
 	if (proposed < 1)
 		proposed = 1;
-	else if (proposed > 5)
-		proposed = 5;
+	else if (proposed > 60)
+		proposed = 60;  // 提高上限到60秒，适应更长的keepalive
 	if (proposed < retryLoopInterval)
 		retryLoopInterval = proposed;
 }
diff --git a/mqtt/MQTTProtocolClient.c b/mqtt/MQTTProtocolClient.c
index 051d494..b83ae10 100644
--- a/mqtt/MQTTProtocolClient.c
+++ b/mqtt/MQTTProtocolClient.c
@@ -633,7 +633,7 @@ void MQTTProtocol_keepalive(time_t now)
 					}
 					else
 					{
-                                                //LOG_I("PINGREQ send success\n");
+                                                LOG_I("PINGREQ send success at %ld\n", (long)now);
 						client->net.lastSent = now;
 						client->ping_outstanding = 1;
 					}
@@ -641,9 +641,25 @@ void MQTTProtocol_keepalive(time_t now)
 			}
 			else
 			{
-				Log(TRACE_PROTOCOL, -1, "PINGRESP not received in keepalive interval for client %s on socket %d, disconnecting", client->clientID, client->net.socket);
-				LOG_I("%s:PINGRESP not received\n",__func__);
-				MQTTProtocol_closeSession(client, 1);
+				// 增加容错：允许ping_outstanding为2时再等待一个周期
+				if (client->ping_outstanding >= 2) {
+					Log(TRACE_PROTOCOL, -1, "PINGRESP not received after 2 keepalive intervals for client %s on socket %d, disconnecting", client->clientID, client->net.socket);
+					LOG_I("%s:PINGRESP not received after 2 attempts\n",__func__);
+					MQTTProtocol_closeSession(client, 1);
+				} else {
+					// 第二次发送PINGREQ
+					if (Socket_noPendingWrites(client->net.socket)) {
+						if (MQTTPacket_send_pingreq(&client->net, client->clientID) != TCPSOCKET_COMPLETE) {
+							Log(TRACE_PROTOCOL, -1, "Error sending second PINGREQ for client %s on socket %d, disconnecting", client->clientID, client->net.socket);
+							LOG_I("%s:Error sending second PINGREQ for client %s on socket %d, disconnecting\n",__func__,client->clientID, client->net.socket);
+							MQTTProtocol_closeSession(client, 1);
+						} else {
+							LOG_I("Second PINGREQ send success at %ld\n", (long)now);
+							client->net.lastSent = now;
+							client->ping_outstanding++;
+						}
+					}
+				}
 			}
 		}
 	}
diff --git a/mqtt/MQTTProtocolOut.c b/mqtt/MQTTProtocolOut.c
index 16d678a..dee6fb5 100644
--- a/mqtt/MQTTProtocolOut.c
+++ b/mqtt/MQTTProtocolOut.c
@@ -178,7 +178,7 @@ int MQTTProtocol_handlePingresps(void* pack, int sock)
 	client = (Clients*)(ListFindItem(bstate->clients, &sock, clientSocketCompare)->content);
 	Log(LOG_PROTOCOL, 21, NULL, sock, client->clientID);
 	client->ping_outstanding = 0;
-        //LOG_I("PINGRESP receive success\n");
+        LOG_I("PINGRESP received successfully, ping_outstanding cleared\n");
 	FUNC_EXIT_RC(rc);
 	return rc;
 }
diff --git a/mqtt_utils/mqtt_utils.c b/mqtt_utils/mqtt_utils.c
index 15e18ba..6f0baee 100644
--- a/mqtt_utils/mqtt_utils.c
+++ b/mqtt_utils/mqtt_utils.c
@@ -419,6 +419,8 @@ void mqtt_utils_connected(void *context, char *cause){
         if (lightbarHeartbeat[i].isOnline) {
             LOG_I("Report again lightbar %08X login\n", lightbarHeartbeat[i].tagCode);
             report_lightbar_login(lightbarHeartbeat[i].tagCode);
+            // 添加短暂延迟，避免MQTT缓冲区溢出
+            usleep(100 * 1000);  // 100ms延迟
         }
     }
     pthread_mutex_unlock(&heartbeatMutex);