diff --git a/yudao-framework/yudao-common/src/main/java/cn/iocoder/yudao/framework/common/util/json/JsonUtils.java b/yudao-framework/yudao-common/src/main/java/cn/iocoder/yudao/framework/common/util/json/JsonUtils.java
index fe55d9bf51..7711ae0d88 100644
--- a/yudao-framework/yudao-common/src/main/java/cn/iocoder/yudao/framework/common/util/json/JsonUtils.java
+++ b/yudao-framework/yudao-common/src/main/java/cn/iocoder/yudao/framework/common/util/json/JsonUtils.java
@@ -262,4 +262,20 @@ public class JsonUtils {
         return objectMapper.convertValue(obj, typeReference);
     }
 
+    /**
+     * 将 Object 转换为 List 类型
+     * <p>
+     * 避免先转 jsonString 再 parseArray 的性能损耗
+     *
+     * @param obj   源对象（可以是 List、数组等）
+     * @param clazz 目标元素类型
+     * @return 转换后的 List
+     */
+    public static <T> List<T> convertList(Object obj, Class<T> clazz) {
+        if (obj == null) {
+            return new ArrayList<>();
+        }
+        return objectMapper.convertValue(obj, objectMapper.getTypeFactory().constructCollectionType(List.class, clazz));
+    }
+
 }
diff --git a/yudao-module-iot/yudao-module-iot-biz/src/main/java/cn/iocoder/yudao/module/iot/controller/admin/device/IotDeviceController.java b/yudao-module-iot/yudao-module-iot-biz/src/main/java/cn/iocoder/yudao/module/iot/controller/admin/device/IotDeviceController.java
index cdc25d803c..deb8cf38b0 100644
--- a/yudao-module-iot/yudao-module-iot-biz/src/main/java/cn/iocoder/yudao/module/iot/controller/admin/device/IotDeviceController.java
+++ b/yudao-module-iot/yudao-module-iot-biz/src/main/java/cn/iocoder/yudao/module/iot/controller/admin/device/IotDeviceController.java
@@ -72,7 +72,7 @@ public class IotDeviceController {
     @Operation(summary = "解绑子设备与网关")
     @PreAuthorize("@ss.hasPermission('iot:device:update')")
     public CommonResult<Boolean> unbindDeviceGateway(@Valid @RequestBody IotDeviceUnbindGatewayReqVO reqVO) {
-        deviceService.unbindDeviceGateway(reqVO.getIds());
+        deviceService.unbindDeviceGateway(reqVO.getIds(), reqVO.getGatewayId());
         return success(true);
     }
 
diff --git a/yudao-module-iot/yudao-module-iot-biz/src/main/java/cn/iocoder/yudao/module/iot/controller/admin/device/vo/device/IotDeviceUnbindGatewayReqVO.java b/yudao-module-iot/yudao-module-iot-biz/src/main/java/cn/iocoder/yudao/module/iot/controller/admin/device/vo/device/IotDeviceUnbindGatewayReqVO.java
index 64215f3f6b..e198193722 100644
--- a/yudao-module-iot/yudao-module-iot-biz/src/main/java/cn/iocoder/yudao/module/iot/controller/admin/device/vo/device/IotDeviceUnbindGatewayReqVO.java
+++ b/yudao-module-iot/yudao-module-iot-biz/src/main/java/cn/iocoder/yudao/module/iot/controller/admin/device/vo/device/IotDeviceUnbindGatewayReqVO.java
@@ -2,6 +2,7 @@ package cn.iocoder.yudao.module.iot.controller.admin.device.vo.device;
 
 import io.swagger.v3.oas.annotations.media.Schema;
 import jakarta.validation.constraints.NotEmpty;
+import jakarta.validation.constraints.NotNull;
 import lombok.Data;
 
 import java.util.Set;
@@ -14,4 +15,8 @@ public class IotDeviceUnbindGatewayReqVO {
     @NotEmpty(message = "子设备编号列表不能为空")
     private Set<Long> ids;
 
+    @Schema(description = "网关设备编号", requiredMode = Schema.RequiredMode.REQUIRED, example = "1")
+    @NotNull(message = "网关设备编号不能为空")
+    private Long gatewayId;
+
 }
diff --git a/yudao-module-iot/yudao-module-iot-biz/src/main/java/cn/iocoder/yudao/module/iot/dal/mysql/device/IotDeviceMapper.java b/yudao-module-iot/yudao-module-iot-biz/src/main/java/cn/iocoder/yudao/module/iot/dal/mysql/device/IotDeviceMapper.java
index c61acf960c..1e3fb2e576 100644
--- a/yudao-module-iot/yudao-module-iot-biz/src/main/java/cn/iocoder/yudao/module/iot/dal/mysql/device/IotDeviceMapper.java
+++ b/yudao-module-iot/yudao-module-iot-biz/src/main/java/cn/iocoder/yudao/module/iot/dal/mysql/device/IotDeviceMapper.java
@@ -8,6 +8,7 @@ import cn.iocoder.yudao.module.iot.controller.admin.device.vo.device.IotDevicePa
 import cn.iocoder.yudao.module.iot.dal.dataobject.device.IotDeviceDO;
 import cn.iocoder.yudao.module.iot.enums.product.IotProductDeviceTypeEnum;
 import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
+import com.baomidou.mybatisplus.core.conditions.update.LambdaUpdateWrapper;
 import jakarta.annotation.Nullable;
 import org.apache.ibatis.annotations.Mapper;
 
@@ -159,4 +160,16 @@ public interface IotDeviceMapper extends BaseMapperX<IotDeviceDO> {
                 .orderByDesc(IotDeviceDO::getId));
     }
 
+    /**
+     * 批量更新设备的网关编号
+     *
+     * @param ids       设备编号列表
+     * @param gatewayId 网关设备编号（可以为 null，表示解绑）
+     */
+    default void updateGatewayIdBatch(Collection<Long> ids, Long gatewayId) {
+        update(null, new LambdaUpdateWrapper<IotDeviceDO>()
+                .set(IotDeviceDO::getGatewayId, gatewayId)
+                .in(IotDeviceDO::getId, ids));
+    }
+
 }
diff --git a/yudao-module-iot/yudao-module-iot-biz/src/main/java/cn/iocoder/yudao/module/iot/service/device/IotDeviceService.java b/yudao-module-iot/yudao-module-iot-biz/src/main/java/cn/iocoder/yudao/module/iot/service/device/IotDeviceService.java
index d69195a98c..e69ebc2da7 100644
--- a/yudao-module-iot/yudao-module-iot-biz/src/main/java/cn/iocoder/yudao/module/iot/service/device/IotDeviceService.java
+++ b/yudao-module-iot/yudao-module-iot-biz/src/main/java/cn/iocoder/yudao/module/iot/service/device/IotDeviceService.java
@@ -305,9 +305,10 @@ public interface IotDeviceService {
     /**
      * 解绑子设备与网关
      *
-     * @param ids 子设备编号列表
+     * @param ids       子设备编号列表
+     * @param gatewayId 网关设备编号
      */
-    void unbindDeviceGateway(Collection<Long> ids);
+    void unbindDeviceGateway(Collection<Long> ids, Long gatewayId);
 
     /**
      * 获取未绑定网关的子设备分页
diff --git a/yudao-module-iot/yudao-module-iot-biz/src/main/java/cn/iocoder/yudao/module/iot/service/device/IotDeviceServiceImpl.java b/yudao-module-iot/yudao-module-iot-biz/src/main/java/cn/iocoder/yudao/module/iot/service/device/IotDeviceServiceImpl.java
index 4104a30617..3b5efb16ff 100644
--- a/yudao-module-iot/yudao-module-iot-biz/src/main/java/cn/iocoder/yudao/module/iot/service/device/IotDeviceServiceImpl.java
+++ b/yudao-module-iot/yudao-module-iot-biz/src/main/java/cn/iocoder/yudao/module/iot/service/device/IotDeviceServiceImpl.java
@@ -14,12 +14,14 @@ import cn.iocoder.yudao.framework.tenant.core.aop.TenantIgnore;
 import cn.iocoder.yudao.framework.tenant.core.util.TenantUtils;
 import cn.iocoder.yudao.module.iot.controller.admin.device.vo.device.*;
 import cn.iocoder.yudao.module.iot.core.biz.dto.IotDeviceAuthReqDTO;
+import cn.iocoder.yudao.module.iot.core.enums.IotDeviceMessageMethodEnum;
 import cn.iocoder.yudao.module.iot.core.enums.IotDeviceStateEnum;
 import cn.iocoder.yudao.module.iot.core.mq.message.IotDeviceMessage;
 import cn.iocoder.yudao.module.iot.core.topic.IotDeviceIdentity;
 import cn.iocoder.yudao.module.iot.core.topic.auth.IotSubDeviceRegisterReqDTO;
 import cn.iocoder.yudao.module.iot.core.topic.auth.IotSubDeviceRegisterRespDTO;
 import cn.iocoder.yudao.module.iot.core.topic.topo.IotDeviceTopoAddReqDTO;
+import cn.iocoder.yudao.module.iot.core.topic.topo.IotDeviceTopoChangeReqDTO;
 import cn.iocoder.yudao.module.iot.core.topic.topo.IotDeviceTopoDeleteReqDTO;
 import cn.iocoder.yudao.module.iot.core.topic.topo.IotDeviceTopoGetRespDTO;
 import cn.iocoder.yudao.module.iot.core.util.IotDeviceAuthUtils;
@@ -29,6 +31,7 @@ import cn.iocoder.yudao.module.iot.dal.dataobject.product.IotProductDO;
 import cn.iocoder.yudao.module.iot.dal.mysql.device.IotDeviceMapper;
 import cn.iocoder.yudao.module.iot.dal.redis.RedisKeyConstants;
 import cn.iocoder.yudao.module.iot.enums.product.IotProductDeviceTypeEnum;
+import cn.iocoder.yudao.module.iot.service.device.message.IotDeviceMessageService;
 import cn.iocoder.yudao.module.iot.service.product.IotProductService;
 import jakarta.annotation.Resource;
 import jakarta.validation.ConstraintViolationException;
@@ -49,6 +52,7 @@ import java.util.*;
 import static cn.iocoder.yudao.framework.common.exception.util.ServiceExceptionUtil.exception;
 import static cn.iocoder.yudao.framework.common.util.collection.CollectionUtils.convertList;
 import static cn.iocoder.yudao.module.iot.enums.ErrorCodeConstants.*;
+import static java.util.Collections.singletonList;
 
 /**
  * IoT 设备 Service 实现类
@@ -69,6 +73,9 @@ public class IotDeviceServiceImpl implements IotDeviceService {
     @Resource
     @Lazy // 延迟加载，解决循环依赖
     private IotDeviceGroupService deviceGroupService;
+    @Resource
+    @Lazy // 延迟加载，解决循环依赖
+    private IotDeviceMessageService deviceMessageService;
 
     @Override
     public Long createDevice(IotDeviceSaveReqVO createReqVO) {
@@ -590,7 +597,8 @@ public class IotDeviceServiceImpl implements IotDeviceService {
         // 3. 清空对应缓存
         deleteDeviceCache(devices);
 
-        // TODO @AI：需要下发网关设备，让其建立拓扑关系吗？（增加）
+        // 4. 下发网关设备拓扑变更通知（增加）
+        sendTopoChangeNotify(gatewayId, IotDeviceTopoChangeReqDTO.STATUS_CREATE, devices);
     }
 
     private void checkSubDeviceCanBind(IotDeviceDO device, Long gatewayId) {
@@ -604,30 +612,25 @@ public class IotDeviceServiceImpl implements IotDeviceService {
 
     @Override
     @Transactional(rollbackFor = Exception.class)
-    public void unbindDeviceGateway(Collection<Long> ids) {
+    public void unbindDeviceGateway(Collection<Long> ids, Long gatewayId) {
         // 1. 校验设备存在
         if (CollUtil.isEmpty(ids)) {
             return;
         }
         List<IotDeviceDO> devices = deviceMapper.selectByIds(ids);
-        if (CollUtil.isNotEmpty(devices)) {
+        devices.removeIf(device -> device.getGatewayId() == null);
+        if (CollUtil.isEmpty(devices)) {
             return;
         }
 
         // 2. 批量更新数据库（将 gatewayId 设置为 null）
-        // TODO @AI：需要搞个方法，专门批量更新某个字段为 null。
-        List<IotDeviceDO> updateList = devices.stream()
-                .filter(device -> device.getGatewayId() != null)
-                .map(device -> new IotDeviceDO().setId(device.getId()).setGatewayId(null))
-                .toList();
-        if (CollUtil.isNotEmpty(updateList)) {
-            deviceMapper.updateBatch(updateList);
-        }
+        deviceMapper.updateGatewayIdBatch(convertList(devices, IotDeviceDO::getId), null);
 
         // 3. 清空对应缓存
         deleteDeviceCache(devices);
 
-        // TODO @AI：需要下发网关设备，让其建立拓扑关系吗？（减少）
+        // 4. 下发网关设备拓扑变更通知（删除）
+        sendTopoChangeNotify(gatewayId, IotDeviceTopoChangeReqDTO.STATUS_DELETE, devices);
     }
 
     @Override
@@ -742,9 +745,8 @@ public class IotDeviceServiceImpl implements IotDeviceService {
                     subDeviceIdentity.getProductKey(), subDeviceIdentity.getDeviceName());
         }
 
-        // 2. 更新数据库
-        // TODO @AI：直接调用更新方法；
-//        unbindDeviceGateway(Collections.singletonList(subDevice.getId()));
+        // 2. 更新数据库（将 gatewayId 设置为 null）
+        deviceMapper.updateGatewayIdBatch(singletonList(subDevice.getId()), null);
         log.info("[deleteDeviceTopo][网关({}/{}) 解绑子设备({}/{})]",
                 gatewayDevice.getProductKey(), gatewayDevice.getDeviceName(),
                 subDevice.getProductKey(), subDevice.getDeviceName());
@@ -782,8 +784,7 @@ public class IotDeviceServiceImpl implements IotDeviceService {
         if (!(message.getParams() instanceof List)) {
             throw exception(DEVICE_SUB_REGISTER_PARAMS_INVALID);
         }
-        // TODO @AI：这个要不也弄到 JsonUtils 里面去？感觉类似 convertObject 呀。
-        List<IotSubDeviceRegisterReqDTO> paramsList = JsonUtils.parseArray(JsonUtils.toJsonString(message.getParams()),
+        List<IotSubDeviceRegisterReqDTO> paramsList = JsonUtils.convertList(message.getParams(),
                 IotSubDeviceRegisterReqDTO.class);
         if (CollUtil.isEmpty(paramsList)) {
             throw exception(DEVICE_SUB_REGISTER_PARAMS_INVALID);
@@ -817,9 +818,13 @@ public class IotDeviceServiceImpl implements IotDeviceService {
             throw exception(DEVICE_SUB_REGISTER_PRODUCT_NOT_GATEWAY_SUB, params.getProductKey());
         }
         // 1.3 查找设备是否已存在
-        // TODO @AI：存在的时候，必须父设备是自己，才返回，否则抛出业务异常；
         IotDeviceDO existDevice = getSelf().getDeviceFromCache(params.getProductKey(), params.getDeviceName());
         if (existDevice != null) {
+            // 校验是否绑定到当前网关
+            if (ObjUtil.notEqual(existDevice.getGatewayId(), gatewayDevice.getId())) {
+                throw exception(DEVICE_GATEWAY_BINDTO_EXISTS,
+                        existDevice.getProductKey(), existDevice.getDeviceName());
+            }
             // 已存在则返回设备信息
             return existDevice;
         }
@@ -840,4 +845,42 @@ public class IotDeviceServiceImpl implements IotDeviceService {
         return SpringUtil.getBean(getClass());
     }
 
+    /**
+     * 发送拓扑变更通知给网关设备
+     *
+     * @param gatewayId  网关设备编号
+     * @param status     变更状态（0-创建, 1-删除）
+     * @param subDevices 子设备列表
+     * @see <a href="https://help.aliyun.com/zh/marketplace/notify-gateway-topology-changes">阿里云 - 通知网关拓扑关系变化</a>
+     */
+    private void sendTopoChangeNotify(Long gatewayId, Integer status, List<IotDeviceDO> subDevices) {
+        if (CollUtil.isEmpty(subDevices)) {
+            return;
+        }
+        // 1. 获取网关设备
+        IotDeviceDO gatewayDevice = deviceMapper.selectById(gatewayId);
+        if (gatewayDevice == null) {
+            log.warn("[sendTopoChangeNotify][网关设备({}) 不存在，无法发送拓扑变更通知]", gatewayId);
+            return;
+        }
+
+        try {
+            // 2.1 构建拓扑变更通知消息
+            List<IotDeviceIdentity> subList = convertList(subDevices, subDevice ->
+                    new IotDeviceIdentity(subDevice.getProductKey(), subDevice.getDeviceName()));
+            IotDeviceTopoChangeReqDTO params = new IotDeviceTopoChangeReqDTO(status, subList);
+            IotDeviceMessage notifyMessage = IotDeviceMessage.requestOf(
+                    IotDeviceMessageMethodEnum.TOPO_CHANGE.getMethod(), params);
+
+            // 2.2 发送消息
+            deviceMessageService.sendDeviceMessage(notifyMessage, gatewayDevice);
+            log.info("[sendTopoChangeNotify][网关({}/{}) 发送拓扑变更通知成功，status={}, subDevices={}]",
+                    gatewayDevice.getProductKey(), gatewayDevice.getDeviceName(),
+                    status, subList);
+        } catch (Exception ex) {
+            log.error("[sendTopoChangeNotify][网关({}/{}) 发送拓扑变更通知失败，status={}]",
+                    gatewayDevice.getProductKey(), gatewayDevice.getDeviceName(), status, ex);
+        }
+    }
+
 }