diff --git a/tests/data/test_index_downloader.py b/tests/data/test_index_downloader.py
index 0888f2a..e724ffa 100644
--- a/tests/data/test_index_downloader.py
+++ b/tests/data/test_index_downloader.py
@@ -131,67 +131,55 @@ def test_download_index_clears_proxy(tmp_path):
     assert "https_proxy" not in os.environ
 
 
-def test_read_index_daily_reads_parquet(tmp_path):
-    """Test that read_index_daily reads index parquet files correctly."""
-    # Import after implementation
+def test_read_index_daily_reads_from_vnpy_db(tmp_path):
+    """read_index_daily 经 vnpy get_database.load_bar_data 读指数日线,返回 DataFrame。
+
+    注:read_index_daily 数据源是 vnpy DbBarData 表(非 parquet);D2 根治拟切 dbbardata,
+    届时 mock 数据源随之更新。当前测 vnpy 路径(与 read_db_daily 同 mock 模式)。
+    """
+    from types import SimpleNamespace
+    from datetime import datetime
     from sanguo_data.datareader import read_index_daily
 
-    # Create test parquet file with same structure as stock data
-    year_dir = tmp_path / "2024"
-    year_dir.mkdir()
-
-    df = pd.DataFrame({
-        "date": ["2024-01-02", "2024-01-03", "2024-01-04"],
-        "open": [3495.0, 3505.0, 3515.0],
-        "high": [3505.0, 3515.0, 3525.0],
-        "low": [3490.0, 3500.0, 3510.0],
-        "close": [3500.0, 3510.0, 3520.0],
-        "volume": [100000, 120000, 110000],
-    })
-    df.to_parquet(year_dir / "sh000300_daily.parquet")
-
     cfg = DataConfig(
-        data_paths={"daily_dir": str(tmp_path)},
+        data_paths={"vnpy_db": str(tmp_path / "q.db")},
         data_sources={}, validation={}, performance={},
     )
+    # vnpy load_bar_data 返回类 BarData 对象(有 datetime/open_price/... 属性)
+    bars = [
+        SimpleNamespace(datetime=datetime(2024, 1, 2), open_price=3495.0,
+                        high_price=3505.0, low_price=3490.0, close_price=3500.0, volume=100000),
+        SimpleNamespace(datetime=datetime(2024, 1, 3), open_price=3505.0,
+                        high_price=3515.0, low_price=3500.0, close_price=3510.0, volume=120000),
+        SimpleNamespace(datetime=datetime(2024, 1, 4), open_price=3515.0,
+                        high_price=3525.0, low_price=3510.0, close_price=3520.0, volume=110000),
+    ]
+    mock_db = MagicMock()
+    mock_db.load_bar_data.return_value = bars
+    # read_index_daily 内 lazy import,patch 源模块属性(同 test_datareader)
+    with patch("vnpy.trader.database.get_database", return_value=mock_db):
+        result = read_index_daily("sh000300", date(2024, 1, 1), date(2024, 12, 31), cfg)
 
-    # Read index daily data
-    result = read_index_daily("sh000300", date(2024, 1, 1), date(2024, 12, 31), cfg)
-
-    # Verify result
     assert len(result) == 3
     assert "close" in result.columns
     assert result["close"].iloc[0] == 3500.0
 
 
-def test_read_index_daily_handles_date_range(tmp_path):
-    """Test that read_index_daily filters by date range correctly."""
-    # Import after implementation
+def test_read_index_daily_passes_date_range_to_vnpy(tmp_path):
+    """read_index_daily 把 start/end 传给 vnpy load_bar_data(日期过滤在 vnpy 层)。"""
+    from datetime import datetime
     from sanguo_data.datareader import read_index_daily
 
-    # Create test parquet file
-    year_dir = tmp_path / "2024"
-    year_dir.mkdir()
-
-    df = pd.DataFrame({
-        "date": ["2024-01-02", "2024-06-15", "2024-12-31"],
-        "open": [3495.0, 3600.0, 3700.0],
-        "high": [3505.0, 3610.0, 3710.0],
-        "low": [3490.0, 3590.0, 3690.0],
-        "close": [3500.0, 3605.0, 3705.0],
-        "volume": [100000, 120000, 110000],
-    })
-    df.to_parquet(year_dir / "sh000300_daily.parquet")
-
     cfg = DataConfig(
-        data_paths={"daily_dir": str(tmp_path)},
+        data_paths={"vnpy_db": str(tmp_path / "q.db")},
         data_sources={}, validation={}, performance={},
     )
+    mock_db = MagicMock()
+    mock_db.load_bar_data.return_value = []
+    with patch("vnpy.trader.database.get_database", return_value=mock_db):
+        read_index_daily("sh000300", date(2024, 1, 1), date(2024, 6, 30), cfg)
 
-    # Read with narrowed date range
-    result = read_index_daily("sh000300", date(2024, 1, 1), date(2024, 6, 30), cfg)
-
-    # Should only get first 2 rows
-    assert len(result) == 2
-    assert result["close"].iloc[0] == 3500.0
-    assert result["close"].iloc[1] == 3605.0
+    # start=date→combine 00:00:00; end=date→combine datetime.max.time()(23:59:59.999999)
+    call = mock_db.load_bar_data.call_args
+    assert call.kwargs["start"] == datetime(2024, 1, 1, 0, 0, 0)
+    assert call.kwargs["end"] == datetime(2024, 6, 30, 23, 59, 59, 999999)