Based on the SimuFact simulation and analysis software, the multi-process of composite forming process for hollow motor shaft of new energy vehicles was numerically simulated and optimized. The results show that the equivalent plastic strain is mainly concentrated near the front end of punch, and the material flows along the two axial ends during the hot extrusion forming process. The equivalent plastic strain at the hollow section of motor  shaft firstly decreases and then increases along the diameter direction after radial forging, and the equivalent plastic strain at the step section increases gradually along the diameter direction. The cold radial forging process parameters optimized by orthogonal experiment are the relative rotation angle of hammer head of 18°, the hammer head depression amount of 1.0 mm, the hammer head die entry angle of 22°, and the billet feeding amount of 1.0 mm. On this basis, a kind of hollow motor shaft for new energy vehicles formed by the composite forming of hot extrusion and cold radial forging was successfully developed, and the influences of the composite forming process on the microstructure and grain refinement of hollow motor shaft were analyzed.