Multidirectional die forging forming method for cylindrical shell of automobile universal joint

The invention provides a multidirectional die forging forming method for a cylindrical shell of an automobile universal joint. The multidirectional die forging forming method comprises the following steps of blanking, pre-forming, pre-forging, finish forging and finish machining. In the pre-forming stage, open type extrusion is used for obtaining a pre-formed piece with a rod handle part and an inner cavity with the same diameter as a final forging, and material volume distribution is preliminarily completed while the forming pressure is reduced; in the pre-forging stage, a pre-forged piece with the wavy upper surface is obtained through a clamping ring in the middle of the upper die; during finish forging, a telescopic mandrel die is used for carrying out inclined raceway forming on the pre-forged piece, and redundant materials in a raceway are upwards extruded and filled to the trough position of the pre-forged piece; and finishing the inclined raceway and grinding off the allowance on the upper surface of