The causes of poor local electrophoresis bad adhesion of metal parts for the bodies are analyzed by EDS spectrum element and SEM analysis methods.The results showed that the surface of the defective steel plate contained chromium and chlorine passivation layer,which affected the phosphating reaction and did not form a loose porous phosphating film structure,which leaded to poor adhesion of electrophoretic paint film.In this case,the abnormal problems of local electrophoretic paint film caused by the failure of matching verification of metal coating and pretreatment electrophoretic material were tested.