如临深渊，如履薄冰
rú​lín​shēn​yuān​rú​lǚ​bó​bīng

to tread on thin ice

  1. 如临深渊 如臨深淵 rú​lín​shēn​yuān
    on the brink of an abyss
    (idiom) as if standing on the edge of a deep pit; used to describe being extremely cautious or feeling very anxious when handling a matter
  2. ， rú
    non-Chinese
  3. 如履薄冰 rú​lǚ​bó​bīng
    extremely cautious
    tread carefully as if walking on thin ice; extremely cautious and wary in one's actions