you can't help laughing是什么意思

科学的翻译是“忍俊不禁”的意思

你忍不住笑.

can't help doing sth 是固定搭配, "忍不住","禁不住"的意思.

I can't help joining them.

I can't help crying.

你忍不住笑。

Can't help doing是一个固定用法

意思是忍不住

cant help doing sth。是忍不住的意思

你情不自禁地笑

你忍不住笑。