用英语应该如何表达“小题大做”呢？

make a thing of/out of something

make a (big) thing (out) of (something)

To exaggerate or put too much focus on a minor issue and make it seemlike a major one.

小题大做是指：把一件小事夸大或者过于关注某件小事，使这件小事看上去好像比天大。

比如：

It was only a small mistake,but he made a really big thing out of it.

就是个小失误，他真是小题大做/大惊小怪。

再看另一个例子：

You got one B.You're making a big a thing out of nothing, if you ask me.Let's not make a thing of this. It's just a minor setback.

如果要我说，你就是得了一次B而已，但是你却表现得大惊小怪。不要把它看做是天大的问题。这只是一个小挫折而已。

编辑：译锐君