a large, heavy hammer with a long handle, used for breaking stones or other heavy material, or for hitting posts into the ground, etc.

used to describe a way of behaving that is too forceful

They accused the prime minister of using sledgehammer tactics. 他们谴责首相大动干戈。

a sledgehammer to crack a nutidiom UK disapproving 杀鸡用牛刀；小题大做