先斩后奏（先斬後奏）　

◎ 先斩后奏 xiānzhǎn-hòuzòu

[execute the criminal first and report to the emperor afterwards—act first and report afterwards] 指执法官先处决罪犯,然后向上奏闻。借以比喻先采取行动,然后再上报

随处审囚刷卷,体察滥官污吏,容老夫先斩后奏。——《元曲选·窦娥冤》