The paper studied the effects of pin velocity,pin diameter,distance of forming trajectory and the width of peening strip corresponding to UPF on the formed arc height of stiffened plate by the orthogonal test.The optimal combination of UPF technological parameters can be obtained. Based on above-mentioned data as the sample data,the multiple regression analysis mathematical model was established.The accuracy of the mathematical model was proved by the sample.The experimental results agree well with the regression analysis data.The multiple regression analysis mathematical model can efficiently predict formed arc height in order to improve the efficiency of the process design.