The invention discloses a linear motor motion control method based on fixed-step speed measurement. Equidistantly arranged Hall switch sensor arrays are used for conducting the position measurement and the speed measurement of the rotor of a linear motor and implementing back-and-forth motion control by stages. The control sequentially comprises a high-speed constant speed stage, a speed reduction stage, a low-speed constant speed stage and a boundary guidance stage. Position PID control, acceleration PID control, speed PID control and position PD control are respectively implemented in each of the four stages. Since the method is based on a simple measurement device and the motion control of the linear motor with variable load capacity can be realized, the invention has the advantages that no grating precise measurement mechanism is required, the problem that the millimeter-scale linear motor positioning control cannot be realized on the dependence of Hall switch sensors only in the prior art is solved, and the cost and the complexity of the system are reduced.