put your money where your mouth is
US /pʊt jʊər ˈmʌn.i wɛr jʊər maʊθ ɪz/
UK /pʊt jʊər ˈmʌn.i wɛr jʊər maʊθ ɪz/

1.
用行动证明, 言行一致
to prove your claims or intentions by actions, especially by spending money
:
•
If you really believe in that startup, then put your money where your mouth is and invest in it.
如果你真的相信那家初创公司,那就用行动证明,投资它。
•
He always talks about helping the poor, but he never actually puts his money where his mouth is.
他总是谈论帮助穷人,但他从未真正用行动证明。