In view of the batch ridge buckle defect appearing in the downstream process for the cold rolling substrate produced by the 1 450 and 2 032 mm hotrolling line, combined with the characteristics of equipment control of two hot rolling production lines, the causes and mechanism of the defects were analyzed from the change of shape control and rolling process specification control. And the results showed that the instability of crown control of hot rolling strip was an important reason for the ridge buckle. By optimizing the control model of HVC profile and adjusting the production process management system, the control principle of "uniform deformation and uniform crown" for the rolling process was realized, the crosssection quality of the strip and crown control was ensured, the occurrence rate of ridge buckle of cold rolled products was reduced by 95.12% compared with the same period of the last cycle, and the product quality was obviously improved.