Gear shaft for automobile and forging method of gear shaft

The invention relates to the technical field of auto spare parts, in particular to a gear shaft for an automobile. The gear shaft comprises multiple shaft bodies in different diameters; the multiple shaft bodies are connected with one another; the central lines of the multiple shaft bodies are located in the same straight line; a shaft pin is formed in the upper end of one side of one shaft body;a shaft hole penetrating through the shaft body is horizontally formed in the middle of one side of one shaft body; the two ends of the shaft hole are conical; and chamfers are formed on the outer sides of the multiple shaft bodies. The invention further provides a forging method of the gear shaft for the automobile. Through addition and reasonable matching of multiple raw materials, the quality,the strength and the corrosion resistance of the gear shaft can be improved effectively, and multiple metals are used as main raw materials, so that the strength of the gear shaft is guaranteed whilethe gear shaft is lightened