Based on the analysis of aerodynamic noise characteristics and acoustic tests of self-ventilated traction motors, the main noise sources were determined, the steady-state flow field of the motor was calculated based on CFD theory, the parameters such as wind resistance and velocity distribution of the system were obtained, and the aerodynamic noise of the motor was predicted and evaluated according to the flow characteristics. Through the optimized design of the inlet and outlet air structure and power fan, the low flow resistance filter and high-efficiency fan are used to reduce noise from the sound source. Acoustic enclosures are used to control noise from the noise propagation path. Optimization for noise reduction. Combined with the characteristics of flow field and acoustic field, the analytical method is used to predict the aerodynamic noise of the optimized motor at high speed, and the deviation between the predicted value and the experimental value is within the acceptable range of the project, and the prediction method has a certain reference value for the rapid evaluation of noise. At the same time, it has been verified by the test that in the high speed range, the noise reduction measures are effective, the noise reduction effect is obvious, and the paper results have been applied for invention patents, which has high engineering application value.