One bark is worse than one bite--------刀子嘴豆腐心（成语）

英文释义
(IDIOM) Expression describing someone whose angry temper is not as dangerous as it appears, like a dog that barks loudly but does not attack.

例句
Our manager seldom smiles and often shouts at us, but his bark is worse than his bite, and he is never vindictive.
我们的经理很少笑，经常冲我们嚷嚷，但他是刀子嘴豆腐心，从不记恨。