Abstract: Aiming at the difficult plastic forming and demoulding problem of double gear, a more reasonable process scheme was developed, and on this basis, the finite element simulation of the scheme was carried out by using DEFORM-3D software, and a better forming effect was obtained, which was verified by the cold extrusion experiment.On this basis, the mold design of spur gears forming and helical gears forming is carried out respectively.Among them, the forming die structure of double gear helical gears part can solve the problem that the helical gears part can not be demoulded.