diff --git a/game_functions.py b/game_functions.py
index 18fe749..8d871db 100644
--- a/game_functions.py
+++ b/game_functions.py
@@ -214,3 +214,24 @@ def get_number_rows(ai_settings, ship_height, alien_height):
     available_space_y = (ai_settings.screen_height - (3 * alien_height) - ship_height)
     number_rows = int(available_space_y / (2 * alien_height))
     return number_rows
+
+
+def update_aliens(ai_settings, screen, stats, sb, ship, aliens, bullets, bossalien, bossbullet):
+    """
+    检查是否有外星人位于屏幕边缘，并更新整群外星人的位置
+    """
+    # 增加：在非BOSS关卡时检查
+    if stats.level != stats.bosslevel:
+        check_fleet_edges(ai_settings, aliens)
+        aliens.update()
+
+        # 检查是否有外星人到达屏幕底端
+        check_aliens_bottom(ai_settings, screen, stats, sb, ship, aliens, bullets)
+
+        # 检测外星人和飞船之间的碰撞
+        if pygame.sprite.spritecollideany(ship, aliens):
+            ship_hit(ai_settings, screen, stats, sb, ship, aliens, bullets, bossalien, bossbullet)
+
+    else:
+        check_bossalien_edges(ai_settings, bossalien)
+        bossalien.update()