Abstract: This paper considers the magnetic field compensation design is considered on the basis of the design of the stator permanent magnet field modulation(S-FMPM) motor, in order to improve the magnetic field modulation effect and provide possibilities for improving the motor torque performance. Based on the theory of airgap magnetic field modulation, the modulation function of the S-FMPM motor is established and the process of magnetic field modulation is demonstrated, and the main airgap harmonics of the torque are determined. In the research process, the rotor partition design is used to form a double airgap motor, so that the airgap magnetic field can obtain a certain compensation effect. Then, the magnetic potential distribution law of the double-airgap motor is discussed, based on which the improvement of magnetic potential utilization effect and the torque improvement are verified. Furthermore, with the aim of improving the magnetic field compensation effect of the motor, the harmonic factor reflecting the magnetic potential utilization effect and the torque compensation factor reflecting the torque compensation effect are defined specifically, and the layered optimization strategy is introduced as the optimization objective respectively. In addition, in order to verify the effectiveness of motor design and optimization analysis, the electromagnetic performance of the motor is evaluated and analyzed. Finally, the prototype is manufactured and the experiment is carried out to verify the rationality and effectiveness of the motor and its optimal design.