In the stamping industry, it is often met with the rolling round parts. The traditional method is to complete the rolling round process after multi-step forming. There are many processes, waste time, waste force, low efficiency and high cost. Generally, the roll forming process includes three processes: angle warping, bending and roll. Accordingly, the forming process of workpiece rounding should be completed by three sets of molds. The first set of molds forms a warping angle at the place where the workpiece is to be rolled, the second set of molds bends somewhere near the warping angle of the workpiece, and the third set of molds rolls the warping part of the workpiece.