A permanent magnet motor with auxiliary slots in the stator teeth is taken as the research object in this article. In the two-dimensional polar coordinate system, the Fourier series method is used to establish an analytical model of the electromagnetic field of surface-mounted permanent magnet motors. The motor solution domain is divided into five sub-domains: permanent magnet, air gap, stator slot, stator slot opening, and auxiliary slot. The electromagnetic properties such as air gap magnetic density, no-load back-EMF, cogging torque, and electromagnetic torque of the motor are calculated. The analytic model is used to analyze the electromagnetic characteristics of surface-mounted permanent magnet motors under no load and load.