The sidewall curl caused by springback widely exists in the U-shape part especially to the advanced high-strength steel. Based on the mechanism of springback and the curl, this paper proposes that the reinforcement is useful to control the U-shaped part’s sidewall curl. The influence law of section parameters such as width, height etc on springback are analyzed. Then a sensitivity analysis was conducted and the prior order of sensitivity factors is given. The result indicates adding the geometric features of reinforcement to part is effective to control the springback and also provides the advice for the springback engineering control in the beginning of part design.