diff --git a/indicators/test_bollinger.py b/indicators/test_bollinger.py
new file mode 100644
index 000000000..1b31e73c2
--- /dev/null
+++ b/indicators/test_bollinger.py
@@ -0,0 +1,89 @@
+"""
+Bollinger Bands 单元测试
+
+Author: 张飞 翼德
+Date: 2026-05-31
+"""
+
+import math
+from bollinger import calc_bollinger
+
+
+def test_basic():
+    """基本功能测试"""
+    prices = [float(10 + i) for i in range(25)]
+    upper, middle, lower = calc_bollinger(prices, period=5)
+    assert len(upper) == 21  # 25 - 5 + 1
+    assert len(middle) == 21
+    assert len(lower) == 21
+
+
+def test_sma_correctness():
+    """验证 middle 等于 SMA"""
+    prices = [10.0, 11.0, 12.0, 13.0, 14.0]
+    upper, middle, lower = calc_bollinger(prices, period=3)
+    # SMA of [10,11,12] = 11.0
+    assert math.isclose(middle[0], 11.0)
+    # SMA of [11,12,13] = 12.0
+    assert math.isclose(middle[1], 12.0)
+    # SMA of [12,13,14] = 13.0
+    assert math.isclose(middle[2], 13.0)
+
+
+def test_upper_lower_symmetry():
+    """验证上下轨关于中轨对称"""
+    prices = [float(44 + i * 0.5 + (i % 3) * 0.2) for i in range(30)]
+    upper, middle, lower = calc_bollinger(prices, period=10)
+    for u, m, l in zip(upper, middle, lower):
+        assert math.isclose(u - m, m - l, rel_tol=1e-9)
+
+
+def test_upper_gt_middle_gt_lower():
+    """上轨 > 中轨 > 下轨"""
+    prices = [10.0, 11.0, 12.0, 13.0, 14.0, 15.0, 16.0, 17.0, 18.0, 19.0]
+    upper, middle, lower = calc_bollinger(prices, period=5)
+    for u, m, l in zip(upper, middle, lower):
+        assert u > m > l
+
+
+def test_num_std_zero():
+    """num_std=0 → 三条线重合"""
+    prices = [10.0, 11.0, 12.0, 13.0, 14.0]
+    upper, middle, lower = calc_bollinger(prices, period=3, num_std=0.0)
+    for u, m, l in zip(upper, middle, lower):
+        assert math.isclose(u, m)
+        assert math.isclose(m, l)
+
+
+def test_insufficient_data():
+    """数据不足 → 空列表"""
+    prices = [10.0, 11.0, 12.0]
+    upper, middle, lower = calc_bollinger(prices, period=5)
+    assert upper == [] and middle == [] and lower == []
+
+
+def test_period_invalid():
+    """period <= 0"""
+    prices = [10.0, 11.0, 12.0]
+    upper, middle, lower = calc_bollinger(prices, period=0)
+    assert upper == [] and middle == [] and lower == []
+    upper, middle, lower = calc_bollinger(prices, period=-1)
+    assert upper == [] and middle == [] and lower == []
+
+
+def test_empty_input():
+    """空输入"""
+    upper, middle, lower = calc_bollinger([], period=5)
+    assert upper == [] and middle == [] and lower == []
+
+
+if __name__ == "__main__":
+    test_basic()
+    test_sma_correctness()
+    test_upper_lower_symmetry()
+    test_upper_gt_middle_gt_lower()
+    test_num_std_zero()
+    test_insufficient_data()
+    test_period_invalid()
+    test_empty_input()
+    print("所有测试通过 ✅")