不由自主

bùyóuzìzhǔ

HSK 7

不由自主 — bùyóuzìzhǔ

can't help; involuntarily
听到这个消息，他不由自主地笑了起来。 tīngdào zhège xiāoxī tā bùyóuzìzhǔ dì xiàoleqǐlái — Hearing the news, he couldn't help but laugh.