The invention discloses a metalworking process of a spline shaft fork of a transmission shaft. The metalworking process comprises the following steps of: carrying out quenching treatment by using a quenching automatic line; milling a small-head end surface and punching central holes at both ends by using a numerical control drilling and milling machine; respectively rough and finely machining allparts of the excircle and an R angle by using a numerical control machine; drilling two earholes by using a combined drilling machine; finely boring two earholes and scribing by using a numerical control milling machine; reaming, machining a circlip groove and machining the outer lateral surface of the two ears by using the numerical control machine; milling a spline by using a numerical control spline milling machine; rounding and deburring; and quenching at a medium frequency by using a medium-frequency quenching machine. The invention can ensure the accuracy of spare parts to the maximum extend, eliminates various errors caused by positioning reference conversion, shortens the whole metalworking process flows, can reduce a great amount of labor and materials, greatly decrease the processing cost, lighten the labor intensity, improve the labor efficiency and save the processing cost.