The radial electromagnetic force in the air gap of the motor acts on the teeth of the stator and is transmitted to the air through the stator and the base, resulting in vibration and noise. Aiming at the prominent problem of noise in actual engineering, the main order and frequency of vibration and noise are obtained by analyzing the radial electromagnetic force. The frequencies under different spatial orders are obtained by analyzing the stator mode of the motor. Considering the salient poles of the motor rotor, a method of opening auxiliary slots in the rotor and increasing the air gap width is proposed to improve the acoustic and vibration characteristics of the motor. The effectiveness of the proposed method is verified by building the finite element model before and after optimization and comparing the electromagnetic force of frequencies 6 f1 and 12 f1 (f1 is the fundamental frequency) under acceleration conditions and the A-weighted sound pressure level under the 24th order and 48th order. Finally, the vibration level and sound pressure level under the 24th order and the 48th order under accelerated conditions are tested on the actual prototype. Experiment results show that the proposed method of opening auxiliary slots on the rotor and changing the air gap width can effectively reduce the vibration and noise of the whole motor.