diff --git a/backend/src/main/java/com/yfd/platform/system/controller/SmsVerifyCodeController.java b/backend/src/main/java/com/yfd/platform/system/controller/SmsVerifyCodeController.java
index 2049d5bf..06e5d6e9 100644
--- a/backend/src/main/java/com/yfd/platform/system/controller/SmsVerifyCodeController.java
+++ b/backend/src/main/java/com/yfd/platform/system/controller/SmsVerifyCodeController.java
@@ -306,6 +306,8 @@ public class SmsVerifyCodeController {
 
         // 已通过电站权限处理过的电站编码
         Set<String> processedStationCodes = new HashSet<>();
+        // 已通过电站分组处理过的流域编码（用于后续差集判断）
+        Set<String> processedBasinCodes = new HashSet<>();
 
         if (!selectedStations.isEmpty()) {
             // 4. 按流域分组：{rvcd -> Set<stcd>}
@@ -345,6 +347,7 @@ public class SmsVerifyCodeController {
                     }
                 }
                 processedStationCodes.addAll(selectedInThisBasin);
+                processedBasinCodes.add(basinCode);
             }
         }
 
@@ -355,7 +358,17 @@ public class SmsVerifyCodeController {
             }
         }
 
-        // 7. 分配默认角色
+        // 7. 处理前端传了流域、但该流域下未匹配到任何选中电站的情况（直接保存流域权限）
+        String rvcdCode = smsVerifyCodeRequest.getRvcdCode();
+        if (StringUtils.isNotEmpty(rvcdCode)) {
+            for (String basinCode : rvcdCode.split(",")) {
+                if (StringUtils.isNotEmpty(basinCode) && !processedBasinCodes.contains(basinCode)) {
+                    addDataScope(userId, "RVCD", basinCode);
+                }
+            }
+        }
+
+        // 8. 分配默认角色
         assignRoleToUser(userId);
         return true;
     }