diff --git a/src/algorithms/find_max_bubble.py b/src/algorithms/find_max_bubble.py
new file mode 100644
index 0000000..e677354
--- /dev/null
+++ b/src/algorithms/find_max_bubble.py
@@ -0,0 +1,16 @@
+"""find_max_bubble — 冒泡排序法找最大值"""
+
+from __future__ import annotations
+
+
+def find_max_bubble(nums: list[int | float]) -> int | float | None:
+    """冒泡排序后取最后一个元素，空列表返回 None。"""
+    if not nums:
+        return None
+    arr = list(nums)  # 不修改原列表
+    n = len(arr)
+    for i in range(n - 1):
+        for j in range(n - 1 - i):
+            if arr[j] > arr[j + 1]:
+                arr[j], arr[j + 1] = arr[j + 1], arr[j]
+    return arr[-1]
diff --git a/src/algorithms/find_max.py b/src/algorithms/find_max_linear.py
similarity index 60%
rename from src/algorithms/find_max.py
rename to src/algorithms/find_max_linear.py
index e71fd53..aac1bce 100644
--- a/src/algorithms/find_max.py
+++ b/src/algorithms/find_max_linear.py
@@ -1,9 +1,9 @@
-"""find_max — 从数字列表中查找最大值"""
+"""find_max_linear — 线性扫描法找最大值"""
 
 from __future__ import annotations
 
 
-def find_max(nums: list[int | float]) -> int | float | None:
+def find_max_linear(nums: list[int | float]) -> int | float | None:
     """返回列表中的最大值，空列表返回 None。"""
     if not nums:
         return None
@@ -12,3 +12,7 @@ def find_max(nums: list[int | float]) -> int | float | None:
         if num > result:
             result = num
     return result
+
+
+# 兼容别名
+find_max = find_max_linear
diff --git a/src/algorithms/find_max_quickselect.py b/src/algorithms/find_max_quickselect.py
new file mode 100644
index 0000000..ae70600
--- /dev/null
+++ b/src/algorithms/find_max_quickselect.py
@@ -0,0 +1,41 @@
+"""find_max_quickselect — 快速选择 partition 思路找最大值"""
+
+from __future__ import annotations
+
+import random
+
+
+def find_max_quickselect(nums: list[int | float]) -> int | float | None:
+    """使用快速选择的 partition 思路直接找最大值，空列表返回 None。"""
+    if not nums:
+        return None
+    arr = list(nums)  # 不修改原列表
+    return _quickselect_max(arr, 0, len(arr) - 1)
+
+
+def _quickselect_max(arr: list[int | float], lo: int, hi: int) -> int | float:
+    """在 arr[lo..hi] 中找最大值。
+
+    Lomuto partition: < pivot 左，>= pivot 右。
+    pivot 落在 store 位置，最大值在 [store, hi]。
+    """
+    if lo == hi:
+        return arr[lo]
+
+    pivot_idx = random.randint(lo, hi)
+    arr[pivot_idx], arr[hi] = arr[hi], arr[pivot_idx]
+
+    pivot = arr[hi]
+    store = lo
+    for i in range(lo, hi):
+        if arr[i] < pivot:
+            arr[store], arr[i] = arr[i], arr[store]
+            store += 1
+    arr[store], arr[hi] = arr[hi], arr[store]
+
+    # store 是 pivot 最终位置
+    # 如果 store == hi，pivot 是当前区间最大值
+    if store == hi:
+        return arr[store]
+    # 否则在 store+1..hi 中继续找（右侧都 >= pivot）
+    return _quickselect_max(arr, store + 1, hi)
diff --git a/tests/test_find_max.py b/tests/test_find_max.py
index 1bbdb1b..4cb875b 100644
--- a/tests/test_find_max.py
+++ b/tests/test_find_max.py
@@ -2,7 +2,7 @@
 
 import pytest
 
-from src.algorithms.find_max import find_max
+from src.algorithms.find_max_linear import find_max
 
 
 class TestFindMax:
diff --git a/tests/test_find_max_three.py b/tests/test_find_max_three.py
new file mode 100644
index 0000000..166b4eb
--- /dev/null
+++ b/tests/test_find_max_three.py
@@ -0,0 +1,63 @@
+"""三种排序算法找最大值 — 单元测试"""
+
+import pytest
+
+from src.algorithms.find_max_linear import find_max_linear
+from src.algorithms.find_max_bubble import find_max_bubble
+from src.algorithms.find_max_quickselect import find_max_quickselect
+
+ALL_ALGOS = [find_max_linear, find_max_bubble, find_max_quickselect]
+
+
+# ── 通用测试（每种算法都跑） ──
+
+@pytest.mark.parametrize("algo", ALL_ALGOS, ids=["linear", "bubble", "quickselect"])
+class TestAllAlgorithms:
+    def test_normal_list(self, algo):
+        assert algo([3, 1, 4, 1, 5, 9, 2, 6]) == 9
+
+    def test_empty_list(self, algo):
+        assert algo([]) is None
+
+    def test_single_element(self, algo):
+        assert algo([42]) == 42
+
+    def test_negative_numbers(self, algo):
+        assert algo([-5, -1, -10, -3]) == -1
+
+    def test_floats(self, algo):
+        assert algo([1.5, 2.7, 0.3, 3.14]) == 3.14
+
+    def test_mixed_int_float(self, algo):
+        assert algo([1, 2.5, 3, 0.1]) == 3
+
+    def test_duplicate_max(self, algo):
+        assert algo([7, 7, 7]) == 7
+
+
+# ── 一致性测试（同输入三法结果相同） ──
+
+class TestConsistency:
+    @pytest.mark.parametrize("nums", [
+        [3, 1, 4, 1, 5, 9, 2, 6],
+        [-5, -1, -10, -3],
+        [1.5, 2.7, 0.3, 3.14],
+        [42],
+        [7, 7, 7],
+        [0, -0.0, 0.0],
+        [100, 200, 50, 150, 75],
+    ])
+    def test_three_algorithms_same_result(self, nums):
+        results = [algo(nums) for algo in ALL_ALGOS]
+        assert all(r == results[0] for r in results), f"Inconsistent: {results}"
+
+    def test_empty_consistency(self):
+        results = [algo([]) for algo in ALL_ALGOS]
+        assert all(r is None for r in results)
+
+    def test_does_not_mutate_input(self):
+        original = [3, 1, 4, 1, 5, 9, 2, 6]
+        for algo in ALL_ALGOS:
+            nums = list(original)
+            algo(nums)
+            assert nums == original, f"{algo.__name__} mutated input"