Abstract: The edge cracking problem of automobile deep drawing thin plate occurred frequently. The four aspects of the poor structure of hot rolled strip edge, the defect of edge, the influence of edge cutting and the control problem of cold rolling process were analyzed. The characteristics of various cold rolling defects were analyzed by optical microscope and scanning electron microscope, and the number of various hot rolling defects that caused the edge cracking of automobile deep drawing thin plate was counted. The results show that the poor microstructure of hot rolled strip edge was the primary reason, accounting for more than 50%, followed by hot rolled strip edge defects. Finally, the corresponding precautions and improvement measures were put forward to improve the quality of cold rolled automobile thin plate products.