diff --git a/yudao-module-iot/yudao-module-iot-gateway/src/main/java/cn/iocoder/yudao/module/iot/gateway/protocol/mqtt/IotMqttProtocol.java b/yudao-module-iot/yudao-module-iot-gateway/src/main/java/cn/iocoder/yudao/module/iot/gateway/protocol/mqtt/IotMqttProtocol.java
index 354cd1b..a1cf47a 100644
--- a/yudao-module-iot/yudao-module-iot-gateway/src/main/java/cn/iocoder/yudao/module/iot/gateway/protocol/mqtt/IotMqttProtocol.java
+++ b/yudao-module-iot/yudao-module-iot-gateway/src/main/java/cn/iocoder/yudao/module/iot/gateway/protocol/mqtt/IotMqttProtocol.java
@@ -332,12 +332,12 @@ public class IotMqttProtocol implements IotProtocol {
                 deviceMessageService.sendDeviceMessage(offlineMessage, connectionInfo.getProductKey(),
                         connectionInfo.getDeviceName(), serverId);
             }
-
-            // 2. 注销连接
-            connectionManager.unregisterConnection(endpoint);
         } catch (Exception e) {
             log.error("[cleanupConnection][清理连接失败，客户端 ID: {}，错误: {}]",
                     endpoint.clientIdentifier(), e.getMessage());
+        } finally {
+            // 2. 注销连接，避免发送离线消息失败时残留连接
+            connectionManager.unregisterConnection(endpoint);
         }
     }
 
diff --git a/yudao-module-iot/yudao-module-iot-gateway/src/main/java/cn/iocoder/yudao/module/iot/gateway/protocol/mqtt/manager/IotMqttConnectionManager.java b/yudao-module-iot/yudao-module-iot-gateway/src/main/java/cn/iocoder/yudao/module/iot/gateway/protocol/mqtt/manager/IotMqttConnectionManager.java
index 3d187c8..a9bb277 100644
--- a/yudao-module-iot/yudao-module-iot-gateway/src/main/java/cn/iocoder/yudao/module/iot/gateway/protocol/mqtt/manager/IotMqttConnectionManager.java
+++ b/yudao-module-iot/yudao-module-iot-gateway/src/main/java/cn/iocoder/yudao/module/iot/gateway/protocol/mqtt/manager/IotMqttConnectionManager.java
@@ -86,7 +86,13 @@ public class IotMqttConnectionManager {
                     deviceId, getEndpointAddress(oldEndpoint));
             // 先清理映射，再关闭连接（避免旧连接处理器干扰）
             connectionMap.remove(oldEndpoint);
-            oldEndpoint.close();
+            try {
+                if (oldEndpoint.isConnected()) {
+                    oldEndpoint.close();
+                }
+            } catch (Exception ignored) {
+                // 连接可能已关闭，忽略异常
+            }
         }
 
         // 注册新连接
@@ -107,7 +113,8 @@ public class IotMqttConnectionManager {
             return;
         }
         Long deviceId = connectionInfo.getDeviceId();
-        deviceEndpointMap.remove(deviceId);
+        // 仅当 deviceEndpointMap 中的 endpoint 是当前 endpoint 时才移除，避免误删新连接
+        deviceEndpointMap.remove(deviceId, endpoint);
         log.info("[unregisterConnection][注销设备连接，设备 ID: {}，连接: {}]", deviceId, getEndpointAddress(endpoint));
     }
 
diff --git a/yudao-module-iot/yudao-module-iot-gateway/src/main/java/cn/iocoder/yudao/module/iot/gateway/protocol/tcp/manager/IotTcpConnectionManager.java b/yudao-module-iot/yudao-module-iot-gateway/src/main/java/cn/iocoder/yudao/module/iot/gateway/protocol/tcp/manager/IotTcpConnectionManager.java
index 20065f1..9349bed 100644
--- a/yudao-module-iot/yudao-module-iot-gateway/src/main/java/cn/iocoder/yudao/module/iot/gateway/protocol/tcp/manager/IotTcpConnectionManager.java
+++ b/yudao-module-iot/yudao-module-iot-gateway/src/main/java/cn/iocoder/yudao/module/iot/gateway/protocol/tcp/manager/IotTcpConnectionManager.java
@@ -61,7 +61,11 @@ public class IotTcpConnectionManager {
                     deviceId, oldSocket.remoteAddress());
             // 先清理映射，再关闭连接
             connectionMap.remove(oldSocket);
-            oldSocket.close();
+            try {
+                oldSocket.close();
+            } catch (Exception ignored) {
+                // 连接可能已关闭，忽略异常
+            }
         }
 
         // 注册新连接
@@ -163,4 +167,4 @@ public class IotTcpConnectionManager {
 
     }
 
-}
\ No newline at end of file
+}
diff --git a/yudao-module-iot/yudao-module-iot-gateway/src/main/java/cn/iocoder/yudao/module/iot/gateway/protocol/websocket/manager/IotWebSocketConnectionManager.java b/yudao-module-iot/yudao-module-iot-gateway/src/main/java/cn/iocoder/yudao/module/iot/gateway/protocol/websocket/manager/IotWebSocketConnectionManager.java
index 92019ff..2dce663 100644
--- a/yudao-module-iot/yudao-module-iot-gateway/src/main/java/cn/iocoder/yudao/module/iot/gateway/protocol/websocket/manager/IotWebSocketConnectionManager.java
+++ b/yudao-module-iot/yudao-module-iot-gateway/src/main/java/cn/iocoder/yudao/module/iot/gateway/protocol/websocket/manager/IotWebSocketConnectionManager.java
@@ -46,9 +46,13 @@ public class IotWebSocketConnectionManager {
         if (oldSocket != null && oldSocket != socket) {
             log.info("[registerConnection][设备已有其他连接，断开旧连接，设备 ID: {}，旧连接: {}]",
                     deviceId, oldSocket.remoteAddress());
-            oldSocket.close();
-            // 清理旧连接的映射
+            // 先清理映射，再关闭连接
             connectionMap.remove(oldSocket);
+            try {
+                oldSocket.close();
+            } catch (Exception ignored) {
+                // 连接可能已关闭，忽略异常
+            }
         }
 
         // 注册新连接