diff --git a/server/app.js b/server/app.js
index a07ab3e..1614d00 100644
--- a/server/app.js
+++ b/server/app.js
@@ -5,6 +5,7 @@ const compression = require('compression');
 
 const config = require('./config');
 const logger = require('./utils/logger');
+const { clearUserCache } = require('./utils/cache');
 const db = require('./db');
 const { router: authRouter, auth } = require('./routes/auth');
 const statsRouter = require('./routes/stats');
@@ -30,6 +31,16 @@ app.use('/api', (req, res, next) => {
   next();
 });
 
+// 全局缓存清除中间件：在写操作完成后清除用户缓存
+app.use('/api', (req, res, next) => {
+  res.once('finish', () => {
+    if (['POST', 'DELETE', 'PUT', 'PATCH'].includes(req.method) && req.user?.id) {
+      clearUserCache(req.user.id);
+    }
+  });
+  next();
+});
+
 app.get('/api/contacts', auth, (req, res) => {
   const field = req.query.field;
   const allowed = ['boss', 'partner', 'source', 'destination'];
diff --git a/server/routes/stats.js b/server/routes/stats.js
index 9c8f14b..e9e0b9f 100644
--- a/server/routes/stats.js
+++ b/server/routes/stats.js
@@ -3,50 +3,11 @@ const db = require('../db');
 const config = require('../config');
 const logger = require('../utils/logger');
 const { getMonthRange, AppError, validateRequired, validateNumber, validateInList } = require('../utils/helpers');
+const { getCached } = require('../utils/cache');
 
 const router = express.Router();
 
-// 内存缓存（限制大小，基于LRU）
-const statsCache = new Map();
-const CACHE_TTL = config.cache.ttl;
-const MAX_CACHE_SIZE = config.cache.maxSize;
-
-function getCached(key, fetchFn) {
-  const cached = statsCache.get(key);
-  if (cached && Date.now() - cached.ts < CACHE_TTL) {
-    // LRU: move to end
-    statsCache.delete(key);
-    statsCache.set(key, cached);
-    return Promise.resolve(cached.data);
-  }
-  if (statsCache.size >= MAX_CACHE_SIZE) {
-    // Delete oldest entry
-    const firstKey = statsCache.keys().next().value;
-    statsCache.delete(firstKey);
-  }
-  return Promise.resolve(fetchFn()).then(data => {
-    statsCache.set(key, { data, ts: Date.now() });
-    logger.debug(`缓存更新: ${key}`);
-    return data;
-  }).catch(err => {
-    logger.error('缓存获取失败:', err.message);
-    throw err;
-  });
-}
-
-// POST/DELETE/PUT/PATCH 后清除当前用户的缓存
-router.use((req, res, next) => {
-  res.once('finish', () => {
-    if (['POST', 'DELETE', 'PUT', 'PATCH'].includes(req.method) && req.user?.id) {
-      for (const key of statsCache.keys()) {
-        if (key.includes(`:${req.user.id}:`)) {
-          statsCache.delete(key);
-        }
-      }
-    }
-  });
-  next();
-});
+// 缓存模块已移至 utils/cache.js
 
 // 格式化本地日期为 YYYY-MM-DD
 function formatLocalDate(date) {
diff --git a/server/utils/cache.js b/server/utils/cache.js
new file mode 100644
index 0000000..b88d023
--- /dev/null
+++ b/server/utils/cache.js
@@ -0,0 +1,69 @@
+/**
+ * 统计数据缓存模块
+ * 基于 LRU 算法的内存缓存
+ */
+const config = require('../config');
+const logger = require('./logger');
+
+const statsCache = new Map();
+const CACHE_TTL = config.cache.ttl;
+const MAX_CACHE_SIZE = config.cache.maxSize;
+
+/**
+ * 获取缓存数据，如果不存在则通过 fetchFn 获取并缓存
+ * @param {string} key 缓存键
+ * @param {Function} fetchFn 获取数据的函数
+ * @returns {Promise} 缓存数据
+ */
+function getCached(key, fetchFn) {
+  const cached = statsCache.get(key);
+  if (cached && Date.now() - cached.ts < CACHE_TTL) {
+    // LRU: move to end
+    statsCache.delete(key);
+    statsCache.set(key, cached);
+    return Promise.resolve(cached.data);
+  }
+
+  // 超出最大缓存数量时，删除最旧的条目
+  if (statsCache.size >= MAX_CACHE_SIZE) {
+    const firstKey = statsCache.keys().next().value;
+    statsCache.delete(firstKey);
+  }
+
+  return Promise.resolve(fetchFn()).then(data => {
+    statsCache.set(key, { data, ts: Date.now() });
+    logger.debug(`缓存更新: ${key}`);
+    return data;
+  }).catch(err => {
+    logger.error('缓存获取失败:', err.message);
+    throw err;
+  });
+}
+
+/**
+ * 清除指定用户的所有缓存
+ * @param {number} userId 用户ID
+ */
+function clearUserCache(userId) {
+  const prefix = `:${userId}:`;
+  for (const key of statsCache.keys()) {
+    if (key.includes(prefix)) {
+      statsCache.delete(key);
+      logger.debug(`缓存清除: ${key}`);
+    }
+  }
+}
+
+/**
+ * 清除所有缓存
+ */
+function clearAllCache() {
+  statsCache.clear();
+  logger.debug('所有缓存已清除');
+}
+
+module.exports = {
+  getCached,
+  clearUserCache,
+  clearAllCache
+};
\ No newline at end of file