diff --git a/backend/iot-device/src/main/java/com/iot/device/controller/TuyaController.java b/backend/iot-device/src/main/java/com/iot/device/controller/TuyaController.java
index c050537..0923be5 100644
--- a/backend/iot-device/src/main/java/com/iot/device/controller/TuyaController.java
+++ b/backend/iot-device/src/main/java/com/iot/device/controller/TuyaController.java
@@ -354,12 +354,10 @@ public class TuyaController {
                 update.setIcon(tuyaDevice.getIcon() != null
                         ? tuyaDevice.getIcon() : existing.getIcon());
                 update.setRemark("涂鸦设备");
-                if (existing.getProductId() == null) {
-                    // model / manufacturer 传 null：涂鸦 OpenAPI 未提供真实型号与厂商，
-                    // 历史误把 productId 填进 model 位，污染了 product 表的型号字段。
-                    update.setProductId(productService.resolveProductId("tuya", tuyaDevice.getProductId(),
-                            null, null, tuyaDevice.getCategory(), tuyaDevice.getDeviceName()));
-                }
+                // 每次同步都校验产品关联（自愈）：产品被删/错挂时自动纠正，
+                // 不再是「仅当 product_id 为空才解析」——后者会让孤儿设备永远无法回收。
+                update.setProductId(productService.ensureDeviceProduct(
+                        existing.getProductId(), "tuya", tuyaDevice.getProductId(), tuyaDevice.getCategory()));
                 deviceMapper.updateById(update);
                 count++;
                 continue;
@@ -383,8 +381,8 @@ public class TuyaController {
             localDevice.setPlatformProductId(tuyaDevice.getProductId());
             localDevice.setIcon(tuyaDevice.getIcon());
             localDevice.setRemark("涂鸦设备");
-            localDevice.setProductId(productService.resolveProductId("tuya", tuyaDevice.getProductId(),
-                    null, null, tuyaDevice.getCategory(), tuyaDevice.getDeviceName()));
+            localDevice.setProductId(productService.ensureDeviceProduct(
+                    localDevice.getProductId(), "tuya", tuyaDevice.getProductId(), tuyaDevice.getCategory()));
             deviceMapper.insert(localDevice);
             count++;
         }
diff --git a/backend/iot-device/src/main/java/com/iot/device/service/ProductService.java b/backend/iot-device/src/main/java/com/iot/device/service/ProductService.java
index 8126e25..9ea3a9c 100644
--- a/backend/iot-device/src/main/java/com/iot/device/service/ProductService.java
+++ b/backend/iot-device/src/main/java/com/iot/device/service/ProductService.java
@@ -43,6 +43,18 @@ public interface ProductService {
     Long resolveProductId(String platform, String platformProductId, String model,
                           String manufacturer, String category, String name);
 
+    /**
+     * 确保设备关联到正确的产品（同步自愈）。
+     *
+     * <p>重构前，涂鸦同步只在 {@code device.product_id IS NULL} 时才解析产品，
+     * 导致产品被删除、设备错挂等情况永远无法自愈。现每次同步都校验：</p>
+     * <ul>
+     *   <li>产品存在且其 platform_product_id 与设备一致 → 保持原关联；</li>
+     *   <li>产品不存在（含已被逻辑删除）或平台产品ID不匹配 → 重新解析/创建产品并返回新ID。</li>
+     * </ul>
+     */
+    Long ensureDeviceProduct(Long currentProductId, String platform, String platformProductId, String deviceType);
+
     /**
      * 存量设备回填：按 model+platform 自动归类建产品并关联 device.product_id
      */
diff --git a/backend/iot-device/src/main/java/com/iot/device/service/impl/ProductServiceImpl.java b/backend/iot-device/src/main/java/com/iot/device/service/impl/ProductServiceImpl.java
index c93b53f..12549d1 100644
--- a/backend/iot-device/src/main/java/com/iot/device/service/impl/ProductServiceImpl.java
+++ b/backend/iot-device/src/main/java/com/iot/device/service/impl/ProductServiceImpl.java
@@ -5,13 +5,19 @@ import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
 import com.iot.common.constants.PlatformType;
 
 import java.util.ArrayList;
+import com.iot.common.exception.BusinessException;
+import com.iot.common.result.ResultCode;
 import com.iot.device.dto.ProductSpec;
 import com.iot.device.entity.Device;
+import com.iot.device.entity.Firmware;
+import com.iot.device.entity.OtaTask;
 import com.iot.device.entity.Product;
 import com.iot.device.entity.ProductAction;
 import com.iot.device.entity.ProductEvent;
 import com.iot.device.entity.ProductProperty;
 import com.iot.device.mapper.DeviceMapper;
+import com.iot.device.mapper.FirmwareMapper;
+import com.iot.device.mapper.OtaTaskMapper;
 import com.iot.device.mapper.ProductActionMapper;
 import com.iot.device.mapper.ProductEventMapper;
 import com.iot.device.mapper.ProductMapper;
@@ -42,6 +48,8 @@ public class ProductServiceImpl implements ProductService {
     private final DeviceMapper deviceMapper;
     private final TuyaCloudService tuyaCloudService;
     private final SpecSemanticResolver semanticResolver;
+    private final FirmwareMapper firmwareMapper;
+    private final OtaTaskMapper otaTaskMapper;
 
     @Override
     @Transactional
@@ -90,6 +98,26 @@ public class ProductServiceImpl implements ProductService {
     @Override
     @Transactional
     public void deleteProduct(Long id) {
+        // 重构：原实现直接删除，会留下 product_id 指向已删产品的孤儿设备。
+        // 现做引用校验：设备/固件/OTA 任务任一引用该产品即拒绝删除。
+        Long devCount = deviceMapper.selectCount(
+                new LambdaQueryWrapper<Device>().eq(Device::getProductId, id));
+        if (devCount != null && devCount > 0) {
+            throw new BusinessException(ResultCode.FAILED,
+                    "该产品下仍有 " + devCount + " 台设备，请先解除设备关联后再删除");
+        }
+        Long fwCount = firmwareMapper.selectCount(
+                new LambdaQueryWrapper<Firmware>().eq(Firmware::getProductId, id));
+        if (fwCount != null && fwCount > 0) {
+            throw new BusinessException(ResultCode.FAILED,
+                    "该产品下仍有 " + fwCount + " 个固件版本，请先删除固件后再删除产品");
+        }
+        Long otaCount = otaTaskMapper.selectCount(
+                new LambdaQueryWrapper<OtaTask>().eq(OtaTask::getProductId, id));
+        if (otaCount != null && otaCount > 0) {
+            throw new BusinessException(ResultCode.FAILED,
+                    "该产品下仍有 " + otaCount + " 个 OTA 升级任务，请先处理后再删除产品");
+        }
         productMapper.deleteById(id);
     }
 
@@ -241,6 +269,24 @@ public class ProductServiceImpl implements ProductService {
         return np.getId();
     }
 
+    /**
+     * 确保设备关联到正确的产品（同步自愈）。
+     *
+     * <p>产品不存在（已被逻辑删除）或平台产品ID不匹配时重新解析，
+     * 使"产品被删 → 设备成孤儿 → 永不回收"的死结可自愈。</p>
+     */
+    @Override
+    @Transactional
+    public Long ensureDeviceProduct(Long currentProductId, String platform, String platformProductId, String deviceType) {
+        if (currentProductId != null && StringUtils.hasText(platformProductId)) {
+            Product p = productMapper.selectById(currentProductId);
+            if (p != null && platformProductId.trim().equals(p.getPlatformProductId())) {
+                return currentProductId;
+            }
+        }
+        return resolveProductId(platform, platformProductId, null, null, deviceType, null);
+    }
+
     /**
      * 清洗型号/厂商入参：与平台产品ID相同、或等于平台编码的，判定为历史错位传入，置空。
      */
@@ -261,19 +307,30 @@ public class ProductServiceImpl implements ProductService {
     @Override
     @Transactional
     public int reconcileDevices() {
+        // 重构：原先只处理 product_id IS NULL 的设备，导致两类问题无法自愈 ——
+        //   1) 产品被删除后，挂在该产品下的设备 product_id 成了孤儿引用，永远不会被修复；
+        //   2) 设备被错误关联到别的产品后，不会被纠正。
+        // 现改为「全量对齐」：对每台有平台产品ID的设备，重新按 (platform, platform_product_id)
+        // 解析产品并校正 product_id；无平台产品ID的设备（纯本地手工设备）跳过。
         List<Device> devices = deviceMapper.selectList(
-                new LambdaQueryWrapper<Device>().isNull(Device::getProductId));
+                new LambdaQueryWrapper<Device>().isNotNull(Device::getPlatformProductId));
         Map<String, Long> cache = new HashMap<>();
         int cnt = 0;
         for (Device d : devices) {
-            String key = (d.getPlatform() == null ? "" : d.getPlatform()) + "|"
-                    + (d.getPlatformProductId() == null ? "" : d.getPlatformProductId());
+            if (!StringUtils.hasText(d.getPlatformProductId())) {
+                continue;
+            }
+            String key = PlatformType.normalize(d.getPlatform()) + "|"
+                    + d.getPlatformProductId().trim();
             Long pid = cache.get(key);
             if (pid == null) {
                 pid = resolveProductId(d.getPlatform(), d.getPlatformProductId(),
                         null, null, d.getDeviceType(), null);
                 cache.put(key, pid);
             }
+            if (pid.equals(d.getProductId())) {
+                continue;
+            }
             d.setProductId(pid);
             deviceMapper.updateById(d);
             cnt++;