堵後門

Simplified: 堵后门

dǔhòumén ㄉㄨˇ ㄏㄡˋ ㄇㄣˊ

    • to close off the channels for getting favours or cheating the system

Character by character

Saying俗语俗語

Idiom惯用语 · Widely known

Literally
block the back door
Meaning
To close off the channels through which people get favours or cheat the system by improper means. Used in a neutral to approving way about anti-corruption measures.

Sources