diff --git a/frontend/src/services/statistics.ts b/frontend/src/services/statistics.ts
index a588303..c900a57 100644
--- a/frontend/src/services/statistics.ts
+++ b/frontend/src/services/statistics.ts
@@ -1,25 +1,27 @@
 // Statistics API Service
 import { apiClient } from './apiClient';
 import type { DashboardSummary, MonthlyStats, TrendStat, MonthlyCompare } from '../types';
-
-const USER_ID = 6; // Mock user ID
+import { useUserStore } from '../stores/userStore';
 
 export const statisticsApi = {
   // API: GET /api/dashboard/summary - 获取仪表盘汇总数据（余额、本月收入/支出、预算进度）
   async getDashboardSummary(): Promise<DashboardSummary> {
-    const response = await apiClient.get<DashboardSummary>('/dashboard/summary', { userId: USER_ID });
+    const userId = useUserStore.getState().userId;
+    const response = await apiClient.get<DashboardSummary>('/dashboard/summary', { userId });
     return response.data;
   },
 
   // API: GET /api/statistics/monthly - 获取月度分类统计数据（按支出分类聚合）
   async getMonthlyStats(month: string): Promise<MonthlyStats> {
-    const response = await apiClient.get<MonthlyStats>('/statistics/monthly', { userId: USER_ID, month });
+    const userId = useUserStore.getState().userId;
+    const response = await apiClient.get<MonthlyStats>('/statistics/monthly', { userId, month });
     return response.data;
   },
 
   // API: GET /api/statistics/trend - 获取日期趋势统计（按天聚合收入/支出）
   async getTrendStats(startDate?: string, endDate?: string): Promise<TrendStat[]> {
-    const params: Record<string, string | number> = { userId: USER_ID };
+    const userId = useUserStore.getState().userId;
+    const params: Record<string, string | number> = { userId };
     if (startDate) params.startDate = startDate;
     if (endDate) params.endDate = endDate;
     const response = await apiClient.get<TrendStat[]>('/statistics/trend', params);
@@ -28,7 +30,8 @@ export const statisticsApi = {
 
   // API: GET /api/statistics/compare - 获取本月与上月对比数据
   async getMonthlyCompare(month: string): Promise<MonthlyCompare> {
-    const response = await apiClient.get<MonthlyCompare>('/statistics/compare', { userId: USER_ID, month });
+    const userId = useUserStore.getState().userId;
+    const response = await apiClient.get<MonthlyCompare>('/statistics/compare', { userId, month });
     return response.data;
   },
 };