diff --git a/backend/services/reward-service/src/infrastructure/external/authorization-service/authorization-service.client.ts b/backend/services/reward-service/src/infrastructure/external/authorization-service/authorization-service.client.ts
index 1c61c068..cf56df35 100644
--- a/backend/services/reward-service/src/infrastructure/external/authorization-service/authorization-service.client.ts
+++ b/backend/services/reward-service/src/infrastructure/external/authorization-service/authorization-service.client.ts
@@ -2,6 +2,17 @@ import { Injectable, Logger } from '@nestjs/common';
 import { ConfigService } from '@nestjs/config';
 import { IAuthorizationServiceClient } from '../../../domain/services/reward-calculation.service';
 
+// authorization-service 返回格式（经过 TransformInterceptor 包装）
+interface AuthorizationServiceResponse<T> {
+  success: boolean;
+  data: T;
+  timestamp: string;
+}
+
+interface NearestAuthorizationResult {
+  accountSequence: number | null;
+}
+
 @Injectable()
 export class AuthorizationServiceClient implements IAuthorizationServiceClient {
   private readonly logger = new Logger(AuthorizationServiceClient.name);
@@ -22,8 +33,10 @@ export class AuthorizationServiceClient implements IAuthorizationServiceClient {
         return null;
       }
 
-      const data = await response.json();
-      return data.accountSequence ? BigInt(data.accountSequence) : null;
+      // authorization-service 返回格式: { success, data: { accountSequence }, timestamp }
+      const result: AuthorizationServiceResponse<NearestAuthorizationResult> = await response.json();
+      const accountSeq = result.data?.accountSequence;
+      return accountSeq ? BigInt(accountSeq) : null;
     } catch (error) {
       this.logger.error(`Error finding nearest authorized province:`, error);
       return null;
@@ -41,8 +54,10 @@ export class AuthorizationServiceClient implements IAuthorizationServiceClient {
         return null;
       }
 
-      const data = await response.json();
-      return data.accountSequence ? BigInt(data.accountSequence) : null;
+      // authorization-service 返回格式: { success, data: { accountSequence }, timestamp }
+      const result: AuthorizationServiceResponse<NearestAuthorizationResult> = await response.json();
+      const accountSeq = result.data?.accountSequence;
+      return accountSeq ? BigInt(accountSeq) : null;
     } catch (error) {
       this.logger.error(`Error finding nearest authorized city:`, error);
       return null;
@@ -60,8 +75,11 @@ export class AuthorizationServiceClient implements IAuthorizationServiceClient {
         return null;
       }
 
-      const data = await response.json();
-      return data.accountSequence ? BigInt(data.accountSequence) : null;
+      // authorization-service 返回格式: { success, data: { accountSequence }, timestamp }
+      const result: AuthorizationServiceResponse<NearestAuthorizationResult> = await response.json();
+      const accountSeq = result.data?.accountSequence;
+      this.logger.debug(`findNearestCommunity for userId=${userId}: result=${accountSeq}`);
+      return accountSeq ? BigInt(accountSeq) : null;
     } catch (error) {
       this.logger.error(`Error finding nearest community:`, error);
       return null;