diff --git a/agri-admin/src/main/resources/application-mqtt.yml b/agri-admin/src/main/resources/application-mqtt.yml
index c99d2b3..b9964bf 100644
--- a/agri-admin/src/main/resources/application-mqtt.yml
+++ b/agri-admin/src/main/resources/application-mqtt.yml
@@ -12,4 +12,4 @@ spring:
     latest-ttl-seconds: 120 #设备最新状态缓存的过期时间（秒）。
     # 自动关闭任务线程池大小
     auto-off-thread-pool-size: 5
-    online-ttl-seconds: 60 # 在线新跳ttl
\ No newline at end of file
+    sub-ttl-seconds: 3600 # 在线新跳ttl
\ No newline at end of file
diff --git a/agri-framework/src/main/java/com/agri/framework/interceptor/MqttMessageHandler.java b/agri-framework/src/main/java/com/agri/framework/interceptor/MqttMessageHandler.java
index 0703736..8dc491e 100644
--- a/agri-framework/src/main/java/com/agri/framework/interceptor/MqttMessageHandler.java
+++ b/agri-framework/src/main/java/com/agri/framework/interceptor/MqttMessageHandler.java
@@ -88,10 +88,6 @@ public class MqttMessageHandler implements SmartLifecycle {
     @Value("${spring.mqtt.default-topic}")
     private String defaultTopic;
 
-    // 新增：前端在线TTL（配合前端心跳，每20秒续一次，TTL建议60秒）
-    @Value("${spring.mqtt.online-ttl-seconds:60}")
-    private int onlineTtlSeconds;
-
     // 新增：最新状态缓存TTL（设备每10秒上报一次，缓存一小段时间即可）
     @Value("${spring.mqtt.latest-ttl-seconds:120}")
     private int latestTtlSeconds;
@@ -100,6 +96,10 @@ public class MqttMessageHandler implements SmartLifecycle {
     @Value("${spring.mqtt.auto-off-thread-pool-size:5}")
     private int autoOffThreadPoolSize;
 
+    // 新增：前端订阅关系TTL（兜底“取消订阅失败/异常退出”）——只维护subc:{clientId}的TTL
+    @Value("${spring.mqtt.subc-ttl-seconds:3600}")
+    private int subcTtlSeconds;
+
     // 优化：统一使用SLF4J日志（JDK 8兼容）
     private static final Logger log = LoggerFactory.getLogger(MqttMessageHandler.class);
 
@@ -350,7 +350,7 @@ public class MqttMessageHandler implements SmartLifecycle {
                     break;
                 }
             }
-            if(hasAutoOffTask(deviceId) && isValidStatus){
+            if (hasAutoOffTask(deviceId) && isValidStatus) {
                 // ✅ 8个功能码状态包：无条件写device:latest:{deviceId}，避免自动关读不到最新状态
                 stringRedisTemplate.opsForValue().set(
                         "device:latest:" + deviceId,
@@ -369,20 +369,18 @@ public class MqttMessageHandler implements SmartLifecycle {
             // 推送给每个订阅的前端
             for (String clientId : subscribedClients) {
 
-                // 新增：只有在线才转发；不在线就清理残留订阅，解决“取消订阅失败兜底”
-                String onlineKey = "online:" + clientId;
-                Boolean online = stringRedisTemplate.hasKey(onlineKey);
-                if (!online) {
-                    // 不在线：从两边索引移除（避免一直给离线前端发）
+                // 方案B：不再依赖online:；改为校验subc:{clientId}是否仍包含deviceId（取消订阅失败/异常退出兜底）
+                Boolean stillSub = stringRedisTemplate.opsForSet().isMember("subc:" + clientId, deviceId);
+                if (!stillSub) {
+                    // 关系不存在：清理sub:{deviceId}残留，避免一直给前端发
                     stringRedisTemplate.opsForSet().remove("sub:" + deviceId, clientId);
-                    stringRedisTemplate.opsForSet().remove("subc:" + clientId, deviceId);
                     continue;
                 }
                 // 前端专属主题：frontend/{clientId}/dtu/{deviceId}/up
                 String frontendTopic = "frontend/" + clientId + "/dtu/" + deviceId + "/listener";
                 // 发布消息
                 mqttMessageSender.publish(frontendTopic, payload);
-                log.info("【设备状态转发】设备{} → 前端{}，主题：{}", deviceId, clientId, frontendTopic);
+                // log.info("【设备状态转发】设备{} → 前端{}，主题：{}", deviceId, clientId, frontendTopic);
             }
         } else {
             // 优化：替换System.out为log.info
@@ -570,12 +568,11 @@ public class MqttMessageHandler implements SmartLifecycle {
                 return;
             }
 
-            // 在线标记：online:{clientId} => 1（带TTL）
-            String onlineKey = "online:" + clientId;
-            stringRedisTemplate.opsForValue().set(onlineKey, "1", onlineTtlSeconds, TimeUnit.SECONDS);
+            // 续期subc:{clientId}
+            stringRedisTemplate.expire("subc:" + clientId, subcTtlSeconds, TimeUnit.SECONDS);
 
             // todo 生产环境不建议打印每次心跳
-            log.debug("【在线心跳】clientId={} 在线TTL={}s payload={}", clientId, onlineTtlSeconds, payload);
+            log.debug("【在线心跳】clientId={} 续期subcTTL={}s payload={}", clientId, subcTtlSeconds, payload);
         } catch (Exception e) {
             log.warn("【在线心跳】处理失败 topic={} msg={}", topic, e.getMessage());
         }
@@ -609,6 +606,10 @@ public class MqttMessageHandler implements SmartLifecycle {
         // 保存订阅关系到Redis
         stringRedisTemplate.opsForSet().add("sub:" + deviceId, clientId);
         stringRedisTemplate.opsForSet().add("subc:" + clientId, deviceId);
+
+        // 新增：订阅成功后给subc设置TTL（兜底“取消订阅失败/异常退出”）
+        stringRedisTemplate.expire("subc:" + clientId, subcTtlSeconds, TimeUnit.SECONDS);
+
         log.info("【订阅管理】前端{}订阅设备{}成功", clientId, deviceId);
     }
 
@@ -697,6 +698,9 @@ public class MqttMessageHandler implements SmartLifecycle {
                     }
                     connection.sAdd(subcKey, deviceIdBytesArray);
 
+                    // 新增：给subc设置TTL（兜底“取消订阅失败/异常退出”）
+                    connection.expire(subcKey, subcTtlSeconds);
+
                     // 执行事务
                     connection.exec();
                     return null;
@@ -707,7 +711,7 @@ public class MqttMessageHandler implements SmartLifecycle {
                     clientId, userId, validDeviceIds.size(), validDeviceIds);
             return validDeviceIds.size();
         } catch (Exception e) {
-            log.error("【全量订阅】前端{}订阅用户{}名下设备失败", clientId, userId, e);
+            log.error("【全量------订阅】前端{}订阅用户{}名下设备失败", clientId, userId, e);
             throw new RuntimeException("全量订阅失败：" + e.getMessage());
         }
     }