割雞焉用牛刀

got3 gai1 jin1 jung6 ngau4 dou1

lit. why use a pole-ax to slaughter a chicken? (idiom) · fig. to waste effort on a trifling matter · also written 殺雞焉用牛刀|杀鸡焉用牛刀[sha1 ji1 yan1 yong4 niu2 dao1]{saat3 gai1 jin1 jung6 ngau4 dou1}