For the rear cross beam of car roof panel, the numerical simulation of its forming process was conducted by Autoform. Based on the results of the initial stimulation, blankholder force and drawbead coefficients nearby defects like fracture and wrinkle were chosen as the design variable, and then process parameters were optimized by Autoform-Sigma. When the optimization was convergent, the optimal result was obtained after 123 iterations and the optimal stamping process parameters were confirmed. The optimal result shows that defects like fracture and wrinkle do not appear in original fracture areas, and the areas of inadequate deformation decreases, as well as principal strain and thinning ratio declines drastically. Based on the above optimal process parameters, stamping tests were carried out, and productions were obtained without defects of wrinkle and crack, which are consistent with the numerical results, and the correctness of stamping process parameters optimization was verified sufficiently.
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