A structure of stator tooth jacking auxiliary slot and rotor outer circle eccentricity was proposed for Permanent Magnet Synchronous Motor (PMSM) to suppress the cogging torque and reduce the vibration and noise of motor thus improve the output performance of PMSM.The analytical formula of distribution function was established for the stator tooth top (before and after slotting) and the main air gap, thus clarified the relationships between the stator slotting and the main magnetic field distribution as well as the cogging torque.At the same time, the influence of the rotor outer circle eccentricity on the cogging torque was analyzed.The optimal parameter matching was obtained through optimization tests and comparative analysis of auxiliary slot parameters including slot number, width, depth, slot spacing and rotor outer circle eccentricity, via finite element method on a built-in 3-phase 8-pole 48-slot V-type PMSM.The results showed that the double rectangular symmetrical slotting on the stator tooth top and the eccentricity of the rotor outer circle can effectively improve the magnetic field distribution of the main air gap and restrain the cogging torque of the motor.The harmonic amplitude of the optimized air gap magnetic density 5, 11, 15 and 17 was decreased significantly, the peak value of the cogging torque of the motor was decreased by 59.6%, and the sine of the back EMF waveform as well as the average torque was increased, thus the motor's output performance was significantly improved.