diff --git a/app/src/main/java/com/ttstd/dialer/manager/MqttManager.java b/app/src/main/java/com/ttstd/dialer/manager/MqttManager.java
index 41a8900..a7d556e 100644
--- a/app/src/main/java/com/ttstd/dialer/manager/MqttManager.java
+++ b/app/src/main/java/com/ttstd/dialer/manager/MqttManager.java
@@ -138,6 +138,17 @@ public class MqttManager {
         return INSTANCE;
     }
 
+    /**
+     * 构建设备离线遗言消息 JSON
+     */
+    private byte[] buildWillPayload() {
+        String sn = DeviceManagerService.getInstance().getSerial();
+        if (TextUtils.isEmpty(sn)) {
+            sn = "";
+        }
+        return ("{\"sn\":\"" + sn + "\",\"status\":\"offline\"}").getBytes(StandardCharsets.UTF_8);
+    }
+
     /**
      * 建立 MQTT 连接（异步，断线后自动重连）
      */
@@ -176,6 +187,12 @@ public class MqttManager {
 
             mMqttClient.connectWith()
                     .keepAlive(30)
+                    .willPublish()
+                        .topic(MQTT_TOPIC_STATUS)
+                        .payload(buildWillPayload())
+                        .qos(com.hivemq.client.mqtt.datatypes.MqttQos.AT_LEAST_ONCE)
+                        .retain(false)
+                        .applyWillPublish()
                     .send()
                     .whenComplete((connAck, throwable) -> {
                         if (throwable != null) {
@@ -240,7 +257,7 @@ public class MqttManager {
     };
 
     /**
-     * 断开 MQTT 连接（主动断开，不会触发自动重连）
+     * 断开 MQTT 连接（主动断开，先发离线消息再断连，不会触发遗言）
      */
     public void disconnect() {
         // 标记主动断开，重连任务与断线监听均据此跳过重连
@@ -248,7 +265,13 @@ public class MqttManager {
         mReconnectHandler.removeCallbacks(mReconnectRunnable);
         stopHeartbeat();
         try {
-            if (mMqttClient != null) {
+            if (mMqttClient != null && mConnected) {
+                // 主动上报离线消息，确保服务端即时感知设备下线
+                String sn = DeviceManagerService.getInstance().getSerial();
+                if (!TextUtils.isEmpty(sn)) {
+                    String offlinePayload = "{\"sn\":\"" + sn + "\",\"status\":\"offline\"}";
+                    publish(MQTT_TOPIC_STATUS, offlinePayload);
+                }
                 mMqttClient.disconnect();
                 mMqttClient = null;
             }
diff --git a/app/src/main/java/com/ttstd/dialer/service/main/MainService.java b/app/src/main/java/com/ttstd/dialer/service/main/MainService.java
index ccfaf31..9a862b3 100644
--- a/app/src/main/java/com/ttstd/dialer/service/main/MainService.java
+++ b/app/src/main/java/com/ttstd/dialer/service/main/MainService.java
@@ -28,6 +28,7 @@ import com.ttstd.dialer.base.BaseService;
 import com.ttstd.dialer.bean.req.SnLocationReq;
 import com.ttstd.dialer.config.CommonConfig;
 import com.ttstd.dialer.manager.ContactSyncManager;
+import com.ttstd.dialer.manager.MqttManager;
 import com.ttstd.dialer.utils.ApkUtils;
 import com.ttstd.dialer.utils.Logger;
 import com.ttstd.dialer.utils.SystemUtils;
@@ -61,6 +62,8 @@ public class MainService extends BaseService implements NetworkUtils.OnNetworkSt
     public void onConnected(NetworkUtils.NetworkType networkType) {
         Logger.e(TAG, "onConnected: networkType = " + networkType);
         ContactSyncManager.getInstance(this).syncPendingContacts();
+        // 网络恢复后立刻尝试 MQTT 重连
+        MqttManager.getInstance().connect();
     }
 
     @Nullable