diff --git a/fibonacci.py b/fibonacci.py
new file mode 100644
index 0000000..0130a41
--- /dev/null
+++ b/fibonacci.py
@@ -0,0 +1,37 @@
+def fibonacci(n: int) -> int:
+    """
+    使用迭代方式计算第 n 个斐波那契数
+
+    Args:
+        n: 要计算的斐波那契数的位置（从 0 开始）
+
+    Returns:
+        第 n 个斐波那契数
+    """
+    if n < 0:
+        raise ValueError("n 必须是非负整数")
+
+    if n == 0:
+        return 0
+
+    if n == 1:
+        return 1
+
+    prev, curr = 0, 1
+    for _ in range(2, n + 1):
+        prev, curr = curr, prev + curr
+
+    return curr
+
+
+if __name__ == "__main__":
+    # 测试代码
+    print("斐波那契数列测试：")
+    for i in range(10):
+        print(f"F({i}) = {fibonacci(i)}")
+
+    # 验证结果
+    expected = [0, 1, 1, 2, 3, 5, 8, 13, 21, 34]
+    for i in range(10):
+        assert fibonacci(i) == expected[i], f"测试失败：F({i})"
+    print("\n所有测试通过！")