Method for machining workpiece by broaching machine

The invention discloses a method for machining a workpiece by a broaching machine. The broaching machine comprises an upper broaching head assembly, a lower broaching head assembly, a broaching tool, a machine body, a fixture assembly and a ram, wherein the upper broaching head assembly is fixedly connected with the ram, the fixture assembly and the ram are slidably connected with the machine body, and the lower broaching head assembly is fixedly connected with the machine body. When the broaching machine is used for machining the workpiece, only one end of the broaching tool needs to be fixed, the broaching tool keeps fixed, and the workpiece moves. The method has the advantages that the machining precision is high, the broaching tool is not easy to damage, occupied space of the integral broaching machine is small, and the like.