In order to solve the problem of poor die life for an automotive gear shaft produced by closed die forging, the die forging process of the gear shaft was simulated by Deform-3D. Firstly, the mechanical properties of the gear shaft material and the wear properties of the die material were studied, and the curve model was fitted. Secondly, based on the established models, the gear shaft forming simulation under the current process was completed to verify the accuracy of the model. At the same time, with the aim of maximizing the die life, the forging process was partially adjusted and optimized. Finally, the optimized process was tested. The results show that when the upper and lower punches adopt differential feed with the speeds of 36 and 54 mm·s-1 respectively, and the initial billet temperature and the preheating temperature of die are 1100 and 360 ℃ respectively, the force and wear of the die are smaller, and the forming quality of the gear shaft forgings is improved to some extent. The trial-produced gear shaft achieves the target quality, which effectively improves the die life.