Consider If you talk the talk, then walk the walk. It means, essentially, if you brag that you can do something, then do it.
It is a variant of the more general scheme talk the talk... walk the walk, defined by Cambridge as:
(informal) If you say that someone talks the talk but does not walk the walk, you mean that they do not act in a way that agrees with the things they say.
An alternative is put up or shut up, defined as follow:
(informal) If you say someone should put up or shut up, you mean they should either take action in order to do what they have been talking about or stop talking about it.
It means, essentially, stop merely talking about doing something, and do it. Put up (do it) or shut up (stop talking about it).
If someone claims that they can do something better than someone else, the second person could respond: "Put up or shut up."
This expression might more accurately reflect the tone of the Chinese expression, since it carries (or can carry) a slight hostility.
The following phrases and their variants are very similar to your translation of "if you know how to do it so well, then you do it!", but are fairly common in situations like the one described, maybe so common as to be considered partially idiomatic:
- If you're so good/clever/skilled, you do it!
- If you're so good, why don't you do it?
- If you're such an expert, why aren't you doing it?
- You do it then... [Contemptuously as one drops the hammer and walks away.]