diff --git a/src/sim/new_avatar.py b/src/sim/new_avatar.py
index 1e5ad07..caaeb5d 100644
--- a/src/sim/new_avatar.py
+++ b/src/sim/new_avatar.py
@@ -507,6 +507,15 @@ class AvatarFactory:
                 if levels[a] < levels[b] + MASTER_LEVEL_MIN_DIFF:
                     levels[a] = min(LEVEL_MAX, levels[b] + MASTER_LEVEL_MIN_DIFF + random.randint(0, MASTER_LEVEL_EXTRA_MAX))
 
+        # 确保年龄不超过境界寿命上限，避免角色一出生就老死
+        # 放在所有关系调整之后，因为关系调整可能会修改年龄和等级
+        for i in range(n):
+            realm = CultivationProgress(levels[i]).realm
+            max_lifespan = Age.REALM_LIFESPAN.get(realm, 100)
+            if ages[i] >= max_lifespan:
+                # 将年龄限制为寿命上限的 80%-95%，保留一定的生存空间
+                ages[i] = int(max_lifespan * random.uniform(0.8, 0.95))
+
         avatars_by_index: list[Avatar] = [None] * n  # type: ignore
         avatars_by_id: dict[str, Avatar] = {}
 
diff --git a/tests/test_new_avatar.py b/tests/test_new_avatar.py
new file mode 100644
index 0000000..ed8d2b5
--- /dev/null
+++ b/tests/test_new_avatar.py
@@ -0,0 +1,84 @@
+"""测试 new_avatar 模块的角色创建逻辑."""
+import pytest
+from src.sim.new_avatar import make_avatars, AvatarFactory, PopulationPlanner
+from src.classes.age import Age
+from src.classes.cultivation import CultivationProgress
+
+
+class TestAgeLifespanConstraint:
+    """测试角色创建时年龄不超过寿命上限的约束."""
+
+    def test_batch_creation_age_within_lifespan(self, base_world):
+        """批量创建角色时，年龄应不超过境界寿命上限.
+
+        注意：只有当随机生成的年龄 >= 寿命上限时才会触发调整，
+        调整后的年龄会在 80%-95% 区间内。正常随机生成的年龄
+        （如 77 岁 / 80 寿命）不会被调整，所以可能接近但不超过上限。
+        """
+        # 创建大量角色以增加覆盖率
+        avatars = make_avatars(base_world, count=100)
+
+        for avatar in avatars.values():
+            max_lifespan = Age.REALM_LIFESPAN.get(
+                avatar.cultivation_progress.realm, 100
+            )
+            assert avatar.age.age < max_lifespan, (
+                f"角色 {avatar.name} 年龄 {avatar.age.age} 超过了"
+                f"境界 {avatar.cultivation_progress.realm} 的寿命上限 {max_lifespan}"
+            )
+
+    def test_batch_creation_no_immediate_death(self, base_world):
+        """批量创建的角色不应该一出生就处于老死状态."""
+        avatars = make_avatars(base_world, count=100)
+
+        for avatar in avatars.values():
+            # 不应该有老死概率
+            death_prob = avatar.age.get_death_probability()
+            assert death_prob == 0.0, (
+                f"角色 {avatar.name} 年龄 {avatar.age.age}/"
+                f"{avatar.age.max_lifespan} 有老死概率 {death_prob}"
+            )
+
+    def test_multiple_batch_creations_consistent(self, base_world):
+        """多次批量创建应该都满足年龄约束."""
+        for _ in range(5):
+            avatars = make_avatars(base_world, count=50)
+            for avatar in avatars.values():
+                max_lifespan = Age.REALM_LIFESPAN.get(
+                    avatar.cultivation_progress.realm, 100
+                )
+                assert avatar.age.age < max_lifespan
+
+
+class TestRealmLifespanMapping:
+    """测试各境界的寿命上限映射."""
+
+    def test_qi_refinement_lifespan(self, base_world):
+        """练气期角色年龄应不超过80岁."""
+        from src.classes.cultivation import Realm
+
+        avatars = make_avatars(base_world, count=100)
+        qi_refinement_avatars = [
+            av for av in avatars.values()
+            if av.cultivation_progress.realm == Realm.Qi_Refinement
+        ]
+
+        for avatar in qi_refinement_avatars:
+            assert avatar.age.age < 80, (
+                f"练气期角色 {avatar.name} 年龄 {avatar.age.age} 超过 80"
+            )
+
+    def test_foundation_establishment_lifespan(self, base_world):
+        """筑基期角色年龄应不超过120岁."""
+        from src.classes.cultivation import Realm
+
+        avatars = make_avatars(base_world, count=100)
+        fe_avatars = [
+            av for av in avatars.values()
+            if av.cultivation_progress.realm == Realm.Foundation_Establishment
+        ]
+
+        for avatar in fe_avatars:
+            assert avatar.age.age < 120, (
+                f"筑基期角色 {avatar.name} 年龄 {avatar.age.age} 超过 120"
+            )