Abstract: There were many cracks in the cable terminal of a automobile battery after assembling on site. The causes of terminal cracking were analyzed by macroscopic observation, chemical composition analysis, fracture analysis, metallographic examination, hardness test and salt spray simulation test. The results show that the residual stress of the battery cable terminal was not effectively released after stamping, and the terminal was exposed to H₂O, O₂, CO₂ and other media during storage, resulting in stress corrosion cracking.