diff --git a/src/main/java/com/peanut/modules/book/controller/BuyOrderController.java b/src/main/java/com/peanut/modules/book/controller/BuyOrderController.java
index 6d254ad..52daa49 100644
--- a/src/main/java/com/peanut/modules/book/controller/BuyOrderController.java
+++ b/src/main/java/com/peanut/modules/book/controller/BuyOrderController.java
@@ -881,26 +881,30 @@ public class BuyOrderController {
      * @param addressRequestVo 地址请求 value object
      * @return R
      */
-    @RequestMapping(value = "/modifyConsigneeAddress", method = RequestMethod.POST)
-    public R modifyOrderAddress(@RequestBody ModifyOrderAddressRequestVo addressRequestVo) {
-        QueryWrapper<BuyOrder> buyOrderQueryWrapper = new QueryWrapper<>();
-        buyOrderQueryWrapper.eq("order_sn", addressRequestVo.getOrderSn());
-        BuyOrder buyOrder = buyOrderService.getOne(buyOrderQueryWrapper);
-        String provinceCode = addressRequestVo.getProvinceCode();
-        QueryWrapper<Province> provinceQueryWrapper = new QueryWrapper<>();
-        provinceQueryWrapper.eq("region_code", provinceCode);
-        Province province = provinceService.getOne(provinceQueryWrapper);
+    private R saveConsigneeAddress(ModifyOrderAddressRequestVo addressRequestVo, BuyOrder buyOrder, Province province) {
+        if (province == null) {
+            String provinceCode = addressRequestVo.getProvinceCode();
+            QueryWrapper<Province> provinceQueryWrapper = new QueryWrapper<>();
+            provinceQueryWrapper.eq("region_code", provinceCode);
+            province = provinceService.getOne(provinceQueryWrapper);
+        }
+        if (province == null) return R.error(500, "省份信息不存在");
         buyOrder.setProvince(province.getProvName());
+
         String cityCode = addressRequestVo.getCityCode();
         QueryWrapper<City> cityQueryWrapper = new QueryWrapper<>();
         cityQueryWrapper.eq("region_code", cityCode);
         City city = cityService.getOne(cityQueryWrapper);
+        if (city == null) return R.error(500, "城市信息不存在");
         buyOrder.setCity(city.getCityName());
+
         String countyCode = addressRequestVo.getCountyCode();
         QueryWrapper<County> countyQueryWrapper = new QueryWrapper<>();
         countyQueryWrapper.eq("region_code", countyCode);
         County county = countyService.getOne(countyQueryWrapper);
+        if (county == null) return R.error(500, "区县信息不存在");
         buyOrder.setDistrict(county.getCountyName());
+
         buyOrder.setShippingUser(addressRequestVo.getConsigneeName());
         buyOrder.setUserPhone(addressRequestVo.getConsigneeMobile());
         buyOrder.setAddress(addressRequestVo.getAddress());
@@ -908,10 +912,86 @@ public class BuyOrderController {
         if (str.contains("+")||str.contains("&")) {
             return R.error(500, "信息中不能含有“+”、“&”符号！");
         }
+
         buyOrderService.updateById(buyOrder);
         return R.ok();
     }
 
+    /**
+     * 修改订单地址
+     *
+     * @param addressRequestVo 地址请求 value object
+     * @return R
+     */
+    @RequestMapping(value = "/modifyConsigneeAddress", method = RequestMethod.POST)
+    public R modifyOrderAddress(@RequestBody ModifyOrderAddressRequestVo addressRequestVo) {
+        QueryWrapper<BuyOrder> buyOrderQueryWrapper = new QueryWrapper<>();
+        buyOrderQueryWrapper.eq("order_sn", addressRequestVo.getOrderSn());
+        BuyOrder buyOrder = buyOrderService.getOne(buyOrderQueryWrapper);
+        if (buyOrder == null) {
+            return R.error(500,"订单不存在");
+        }
+
+        // 后台修改地址时，addressId 设为 0
+        buyOrder.setAddressId(0);
+
+        return saveConsigneeAddress(addressRequestVo, buyOrder, null);
+    }
+
+    /**
+     * APP修改订单地址
+     *
+     * @param addressRequestVo 地址请求 value object
+     * @return R
+     */
+    @RequestMapping(value = "/modifyConsigneeAddressApp", method = RequestMethod.POST)
+    public R modifyOrderAddressApp(@RequestBody ModifyOrderAddressRequestVo addressRequestVo) {
+        QueryWrapper<BuyOrder> buyOrderQueryWrapper = new QueryWrapper<>();
+        buyOrderQueryWrapper.eq("order_sn", addressRequestVo.getOrderSn());
+        BuyOrder buyOrder = buyOrderService.getOne(buyOrderQueryWrapper);
+        if (buyOrder == null) {
+            return R.error(500,"订单不存在");
+        }
+
+        MyUserEntity userEntity = myUserService.getById(ShiroUtils.getUId());
+        if (userEntity == null) return R.error(500, "用户不存在");
+
+        Integer currentUserId = userEntity.getId();
+        if (!currentUserId.equals(buyOrder.getUserId())) {
+            return R.error(500, "无权修改该订单地址");
+        }
+
+        String provinceCode = addressRequestVo.getProvinceCode();
+        QueryWrapper<Province> provinceQueryWrapper = new QueryWrapper<>();
+        provinceQueryWrapper.eq("region_code", provinceCode);
+        Province province = provinceService.getOne(provinceQueryWrapper);
+        if (province == null) {
+            return R.error(500, "省份信息不存在");
+        }
+
+        // 仅 App 用户：已支付运费时，新地址省份 code 必须与原订单省份 code 相同；无运费可改任意省
+        if (buyOrder.getShippingMoney() != null && buyOrder.getShippingMoney().compareTo(BigDecimal.ZERO) > 0) {
+            QueryWrapper<Province> oldProvinceQueryWrapper = new QueryWrapper<>();
+            oldProvinceQueryWrapper.eq("prov_name", buyOrder.getProvince());
+            Province oldProvince = provinceService.getOne(oldProvinceQueryWrapper);
+            if (oldProvince == null || !provinceCode.equals(oldProvince.getRegionCode())) {
+                return R.error(500, "该订单已支付运费，只能修改为同省份地址");
+            }
+        }
+
+        // App 传入 addressId 时更新
+        if (addressRequestVo.getAddressId() != null) {
+            buyOrder.setAddressId(addressRequestVo.getAddressId());
+        } else {
+            buyOrder.setAddressId(0);
+        }
+        // 仅 App 用户修改时 addressModified 每次 +1；后台修改不加
+        buyOrder.setAddressModified(buyOrder.getAddressModified() + 1);
+
+
+        return saveConsigneeAddress(addressRequestVo, buyOrder, province);
+    }
+
     /**
      * 获取订单地址
      *
diff --git a/src/main/java/com/peanut/modules/book/vo/request/ModifyOrderAddressRequestVo.java b/src/main/java/com/peanut/modules/book/vo/request/ModifyOrderAddressRequestVo.java
index 80fcd15..d565644 100644
--- a/src/main/java/com/peanut/modules/book/vo/request/ModifyOrderAddressRequestVo.java
+++ b/src/main/java/com/peanut/modules/book/vo/request/ModifyOrderAddressRequestVo.java
@@ -37,4 +37,8 @@ public class ModifyOrderAddressRequestVo {
      * 详细地址
      */
     private String address;
+    /**
+     * 用户地址 ID（App 从地址列表选择时传入；后台管理员修改时会将订单 addressId 置为 null）
+     */
+    private Integer addressId;
 }