皮軟骨頭硬

Simplified: 皮软骨头硬

píruǎngǔtouyìng ㄆㄧˊ ㄖㄨㄢˇ ㄍㄨˇ ˙ㄊㄡ ㄧㄥˋ

    • gentle and yielding in appearance but strong and firm inside

Character by character

Saying俗语俗語

Idiom惯用语 · Rarely used now

Literally
soft skin, hard bones
Meaning
Describes someone who seems gentle and yielding but is strong and firm inside. Approving.

Sources