Permanent magnet synchronous motors are widely used in various fields for the advantages of high power density, high efficiency and high reliability. This paper analyzes the cogging torque of generators with different slot and pole coordination, and selects the optimal pole–slot ratio. Then, this paper analyzes the structural differences between the outer rotor and the inner rotor of permanent magnet synchronous motor, and selects the structural form of the outer rotor for analysis. Based on the electromagnetic design parameters of the motor, a two-dimensional finite element model is established in Maxwell to simulate and analyze the performance at no-load, rated load and short-circuit. The internal magnetic field, the distortion rate of voltage waveform, torque and short circuit current of the motor are studied, and the demagnetization of the permanent magnet under the worst operating condition is investigated. The simulation results show that the design scheme meets the design objectives.