In the field of high-voltage three-phase asynchronous motor manufacturing, stator punching piece, rotor punching piece is a necessary part, rotor punching piece through the stacking, casting aluminium, wear shaft, manufactured into cast aluminium rotor, cast aluminium rotor machined with a lathe and then manufactured into a rotor, made from the cast aluminium rotor into a rotor, there will be a machining allowance, the size of the machining allowance determines the efficiency of the production, in order to improve the efficiency of the production, reduce machining allowances, when manufacturing stator punches and rotor punches,special stamping dies are required to ensure that processing allowances are reduced and production efficiency is increased.