diff --git a/settings.py b/settings.py
index 2d44ed9..067c71f 100644
--- a/settings.py
+++ b/settings.py
@@ -28,4 +28,10 @@ class Settings():
         # 外星人点数的提高速度
         self.score_scale = 1.01
 
-        self.initialize_dynamic_settings()
\ No newline at end of file
+        self.initialize_dynamic_settings()
+        
+        # fleet_direction为1表示向右移，为-1表示向左移
+        self.fleet_direction = 1
+
+    def initialize_dynamic_settings(self):
+        """初始化随游戏进行而变化的设置"""