The stretchbending process of stainless steel roof bending beam with angle section and variable curvature for a subway vehicle was studied by numerical simulation, and the causes of wrinkle defects in such components were analyzed. Then, the influences of sidewall height, die clearance and stretching amount on wrinkling trend were studied, and the optimum parameters of die and process were found. Finally, the verification test was carried out, and the high quality stretrchbending parts were obtained. The results show that the sidewall height has a significant influence on the wrinkling defect, and increasing the sidewall height can aggravate wrinkling defect when the length of flange is fixed. However, the die clearance has a certain influence on the wrinkling defect, and reducing the die clearance can reduce the wrinkling defect, but the wrinkling cannot be completely eliminated. The stretching amount has a great influence on the wrinkling defect, and increasing the stretching amount can effectively control the wrinkling.  When the stretching amount increases to 7.5%,  the wrinkling substantially disappears.