To enhance the production quality and efficiency of an automotive gear shaft, the forging process was conducted for manufacturing. Firstly, two forging forming schemes were proposed, utilizing integral punch and combined punch structures, respectively. The forming conditions of gear shaft were analyzed by using Deform-3D, and the forgings temperature, punch force and minimum clamping force were compared comprehensively. Secondly, the extrusion method of the combined punch was optimized, and the quality of forgings could still be guaranteed after optimization. At the same time, the punch force and the minimum clamping force reduced significantly, effectively improving the service life of die. Finally, the trial forging of gear shaft was conducted, the produced samples of gear shaft at various stages could match the simulation results, confirming the accuracy of the simulation process. Inspection reveals that the formed gear shafts have no obvious defects and are of good quality, which fully meets the dimensional requirements of the process, demonstrating the feasibility of the developed forging process.