diff --git a/indicators/atr.py b/indicators/atr.py
new file mode 100644
index 000000000..31f6ba472
--- /dev/null
+++ b/indicators/atr.py
@@ -0,0 +1,104 @@
+"""
+ATR (Average True Range) 指标计算函数
+使用 Wilder 平滑方法
+
+Author: 张飞 翼德
+Date: 2026-06-01
+"""
+
+from typing import List
+
+
+def calc_atr(
+    highs: List[float],
+    lows: List[float],
+    closes: List[float],
+    period: int = 14,
+) -> List[float]:
+    """计算 ATR (Average True Range)。
+
+    Args:
+        highs: 最高价序列
+        lows: 最低价序列
+        closes: 收盘价序列
+        period: ATR 周期，默认 14
+
+    Returns:
+        ATR 值列表。数据不足 period+1 时返回空列表。
+    """
+    n = len(closes)
+    if period <= 0 or n < period + 1:
+        return []
+    if n != len(highs) or n != len(lows):
+        raise ValueError("highs, lows, closes 长度必须一致")
+
+    # 计算 True Range（需要前一根收盘价，从 i=1 开始）
+    tr: List[float] = []
+    for i in range(1, n):
+        tr.append(max(
+            highs[i] - lows[i],
+            abs(highs[i] - closes[i - 1]),
+            abs(lows[i] - closes[i - 1]),
+        ))
+
+    # 数据不足 period 个 TR
+    if len(tr) < period:
+        return []
+
+    # 初值：前 period 个 TR 的 SMA
+    result: List[float] = []
+    atr = sum(tr[:period]) / period
+    result.append(atr)
+
+    # 后续用 Wilder 平滑
+    for i in range(period, len(tr)):
+        atr = (atr * (period - 1) + tr[i]) / period
+        result.append(atr)
+
+    return result
+
+
+# ---------- 单元测试 ----------
+if __name__ == "__main__":
+    # 基本用例
+    highs  = [12.0, 13.0, 11.0, 14.0, 13.0, 15.0, 14.0, 16.0, 15.0, 14.0, 13.0, 12.0, 14.0, 15.0, 16.0, 14.0]
+    lows   = [10.0, 11.0,  9.0, 12.0, 11.0, 13.0, 12.0, 14.0, 13.0, 12.0, 11.0, 10.0, 12.0, 13.0, 14.0, 12.0]
+    closes = [11.0, 12.0, 10.0, 13.0, 12.0, 14.0, 13.0, 15.0, 14.0, 13.0, 12.0, 11.0, 13.0, 14.0, 15.0, 13.0]
+
+    atr = calc_atr(highs, lows, closes, period=5)
+    assert len(atr) > 0
+
+    # 手动验证第一个 ATR
+    trs = []
+    for i in range(1, 6):
+        trs.append(max(highs[i]-lows[i], abs(highs[i]-closes[i-1]), abs(lows[i]-closes[i-1])))
+    expected_first = sum(trs) / 5
+    assert abs(atr[0] - expected_first) < 1e-9
+
+    # 验证后续平滑
+    prev = atr[0]
+    for i in range(1, len(atr)):
+        idx = i + 5  # 对应 tr 的索引
+        tr_val = max(highs[idx]-lows[idx], abs(highs[idx]-closes[idx-1]), abs(lows[idx]-closes[idx-1]))
+        expected = (prev * 4 + tr_val) / 5
+        assert abs(atr[i] - expected) < 1e-9
+        prev = atr[i]
+
+    # ATR 值应为正
+    for v in atr:
+        assert v > 0
+
+    # 数据不足 → 空列表
+    assert calc_atr([1, 2], [1, 2], [1, 2], period=14) == []
+
+    # period+1 刚好
+    assert len(calc_atr(highs[:6], lows[:6], closes[:6], period=5)) == 1
+
+    # period <= 0
+    assert calc_atr(highs, lows, closes, period=0) == []
+    assert calc_atr(highs, lows, closes, period=-1) == []
+
+    # 空数据
+    assert calc_atr([], [], [], period=5) == []
+
+    print("所有测试通过 ✅")