diff --git a/app/storage_manager.py b/app/storage_manager.py
index a3cf410..7a2e05b 100644
--- a/app/storage_manager.py
+++ b/app/storage_manager.py
@@ -7,13 +7,13 @@ from datetime import datetime
 from sqlalchemy import text
 from sqlalchemy.orm import sessionmaker
 
-from app.config import REDIS_TTL_SECONDS
+from app.config import CACHE_TTL_SECONDS, REDIS_TTL_SECONDS
 from app.models import MarketData, SymbolTimestamp
 
 logger = logging.getLogger(__name__)
 
 # Redis 缓存 TTL：读取自 app.config.REDIS_TTL_SECONDS（默认 30 天）
-CACHE_TTL_SECONDS = REDIS_TTL_SECONDS
+# 业务缓存有效期：读取自 app.config.CACHE_TTL_SECONDS（默认 300 秒）
 
 
 class StorageManager:
@@ -188,7 +188,7 @@ class StorageManager:
                     try:
                         self.redis_client.setex(
                             cache_key,
-                            CACHE_TTL_SECONDS,
+                            REDIS_TTL_SECONDS,
                             json.dumps(result, ensure_ascii=False),
                         )
                     except Exception as e:
@@ -383,7 +383,7 @@ class StorageManager:
                     try:
                         self.redis_client.setex(
                             cache_key,
-                            CACHE_TTL_SECONDS,
+                            REDIS_TTL_SECONDS,
                             json.dumps(result, ensure_ascii=False),
                         )
                     except Exception as e:
@@ -471,7 +471,7 @@ class StorageManager:
                 try:
                     self.redis_client.setex(
                         cache_key,
-                        CACHE_TTL_SECONDS,
+                        REDIS_TTL_SECONDS,
                         json.dumps(cache_value, ensure_ascii=False),
                     )
                 except Exception as e:
@@ -542,7 +542,7 @@ class StorageManager:
             try:
                 self.redis_client.setex(
                     cache_key,
-                    CACHE_TTL_SECONDS,
+                    REDIS_TTL_SECONDS,
                     json.dumps(cache_value, ensure_ascii=False),
                 )
             except Exception as e:
@@ -654,7 +654,7 @@ class StorageManager:
                 try:
                     self.redis_client.setex(
                         cache_key,
-                        CACHE_TTL_SECONDS,
+                        REDIS_TTL_SECONDS,
                         json.dumps(cache_value, ensure_ascii=False),
                     )
                 except Exception as e:
@@ -667,7 +667,7 @@ class StorageManager:
             try:
                 self.redis_client.setex(
                     timestamp_cache_key,
-                    CACHE_TTL_SECONDS,
+                    REDIS_TTL_SECONDS,
                     json.dumps(timestamp_cache_value, ensure_ascii=False),
                 )
             except Exception as e:
diff --git a/tests/test_storage_manager.py b/tests/test_storage_manager.py
index 9eb77db..18d3874 100644
--- a/tests/test_storage_manager.py
+++ b/tests/test_storage_manager.py
@@ -2,7 +2,7 @@ import importlib
 import json
 import logging
 import time
-from datetime import datetime
+from datetime import datetime, timedelta
 from unittest.mock import MagicMock, patch
 
 import pytest
@@ -348,6 +348,57 @@ class TestStorageManagerReadLogic:
         )
 
 
+    def test_is_fresh_true_within_cache_ttl(self):
+        """数据在 CACHE_TTL_SECONDS（默认 300 秒）内时 is_fresh 为 True。"""
+        manager = StorageManager(redis_client=None, mysql_engine=None)
+        fetched_at = datetime(2026, 7, 4, 10, 0, 0)
+        now = fetched_at + timedelta(seconds=60)
+
+        mock_datetime = MagicMock()
+        mock_datetime.now.return_value = now
+        mock_datetime.fromisoformat = datetime.fromisoformat
+
+        with patch("app.storage_manager.datetime", mock_datetime):
+            result = manager._merge_period_results(
+                "AG2606",
+                "futures",
+                {
+                    "5min": {
+                        "current_price": 123.45,
+                        "timestamp": fetched_at.isoformat(),
+                        "candles": [],
+                    }
+                },
+            )
+
+        assert result["is_fresh"] is True
+
+    def test_is_fresh_false_beyond_cache_ttl(self):
+        """数据超过 CACHE_TTL_SECONDS（默认 300 秒）时 is_fresh 为 False。"""
+        manager = StorageManager(redis_client=None, mysql_engine=None)
+        fetched_at = datetime(2026, 7, 4, 10, 0, 0)
+        now = fetched_at + timedelta(seconds=301)
+
+        mock_datetime = MagicMock()
+        mock_datetime.now.return_value = now
+        mock_datetime.fromisoformat = datetime.fromisoformat
+
+        with patch("app.storage_manager.datetime", mock_datetime):
+            result = manager._merge_period_results(
+                "AG2606",
+                "futures",
+                {
+                    "5min": {
+                        "current_price": 123.45,
+                        "timestamp": fetched_at.isoformat(),
+                        "candles": [],
+                    }
+                },
+            )
+
+        assert result["is_fresh"] is False
+
+
 class TestStorageManagerWriteLogic:
     """StorageManager 双写一致性测试。"""
 
@@ -792,18 +843,22 @@ class TestStorageManagerConfig:
     """配置读取相关测试。"""
 
     def test_redis_ttl_reads_config_value(self):
-        """StorageManager 应读取 app.config.REDIS_TTL_SECONDS 作为默认 TTL。"""
+        """StorageManager 应分别读取 app.config.REDIS_TTL_SECONDS 与 CACHE_TTL_SECONDS。"""
         import app.config as config
         import app.storage_manager as sm
 
-        original_ttl = config.REDIS_TTL_SECONDS
+        original_redis_ttl = config.REDIS_TTL_SECONDS
+        original_cache_ttl = config.CACHE_TTL_SECONDS
         original_singleton = sm._storage_manager
         config.REDIS_TTL_SECONDS = 1234
+        config.CACHE_TTL_SECONDS = 5678
         try:
             importlib.reload(sm)
-            assert sm.CACHE_TTL_SECONDS == 1234
+            assert sm.REDIS_TTL_SECONDS == 1234
+            assert sm.CACHE_TTL_SECONDS == 5678
         finally:
-            config.REDIS_TTL_SECONDS = original_ttl
+            config.REDIS_TTL_SECONDS = original_redis_ttl
+            config.CACHE_TTL_SECONDS = original_cache_ttl
             importlib.reload(sm)
             sm._storage_manager = original_singleton