大炮打麻雀

大炮打麻雀

Literally means:

kill a sparrow with a cannon

Actually means:

break a butterfly on the wheel

It is not necessary to use a cannon to kill a sparrow.

Figuratively this phrase means handling a small thing at a huge expense, or treating a minor thing as an important one. It implies that it is not necessary or worthwhile. It connotes the speaker's disapproval or criticism of such a way of doing things.

打小麻雀根本没必要用大炮。

比喻办小事花大代价，或把小事情当大事情来做。含有没有必要，不值得的意思。表示了说话人不满或批评这种行为。