Abstract: Mass fracture appearance happened to 60Si2MnA steel leaf springs after service only for 10 h,and means such as chemical compositions analysis,hardness testing,metallographic examination and micro fracture analysis were used to find out the fracture reasons.The results show that the hydrogen evolution reaction happening in the process of pickling and electroplating made the leaf springs produce hydrogen embrittlement phenomenon.At the same time,the improper heat treatment operations resulted in abnormal microstructure and higher hardness than the technical requirement,which accelerated the hydrogen embrittlement tendency of the leaf springs and eventually led to hydrogen embrittlement fracture under the action of external stress.