sb's bark is worse than his/her bite

If someone's bark is worse than their bite, they are not as unpleasant or frightening as they seem.

刀子嘴豆腐心;言语比行动吓人

A bark is the noise that a dog makes. Most often a dog's bark is used as a warning and the animal is not planning to attack or bite someone. This is where the phrase comes from.

吠声是狗发出的声音。大多数情况下，狗的叫声是作为一种警告，而不是打算攻击或咬人的行为。这就是这个短语的由来。

She always scolded her children, but they knew her bark was worse than her bite.

她动不动就骂她的孩子们，但孩子们都知道她是刀子嘴豆腐心。