at night 的意思是during any night，通常表泛指。在非正式文体中，可用复数名词不加介词来指反复进行的活动。in the night的意思是during one particular night，通常表特指。

at night和in the night的区别

at night的用法

1、It was late at night, and all was quiet in the village.

夜深了，村子里沉静下来。

2、The couple wed late at night in front of just nine guests

深夜这对情侣在仅有的9位宾客面前举行了婚礼。

3、By day a woman could safely walk the streets, but at night the pavements became dangerous

白天的时候，妇女可以安全地在街上行走，而到了夜晚人行道上会变得很危险。

4、Thieves broke into the manor at night.

小偷晚上闯进了庄园。

5、I don't ride the subway late at night.

我深夜不坐地铁。

in the night 的用法

1、I woke up twice in the night.

我夜里醒过两次。

2、Her chiffon skirt was fluttering in the night breeze.

她的雪纺裙在晚风中飘动着。

3、He lost his way in the night.

黑夜中他迷途了。

4、Stars twinkled in the night sky.

夜空中群星闪动。

5、There was a dull red glow in the night sky above the steelworks.

夜晚炼钢厂的上空闪着暗红色的光。