pull strings

to secretly use the influence you have over important people in order to get something or to help someone

托关系，走后门

I may be able to pull a few strings if you need the document urgently.

你急需那份文件的话我也许能托托关系。

l heard that Tina got the promotion because her father had been pulling strings behind the scenes.

我听说缇娜被提拔是因为她父亲一直在暗中拉关系。