In order to reduce the noise of the crankshaft pulley，the fluid simulation software STAR ccm+ is used to establish a flow field simulation model，and the acoustic software LMS Virtual lab is used to simulate the aerodynamic noise of the pulley and analyze the structural and acoustic cavity modes of the pulley. The simulation analysis results show that when pulley rotates at high speed，the groove flow velocity between the pulley and the front cover of the gear chamber is uneven，and periodic pressure pulsation is generated on the groove surface，which is the main source of aerodynamic noise of the pulley. A relatively closed cavity is formed inside the groove，and the first-order modal frequency of the acoustic cavity is close to the excitation frequency of the noise source，which increases the noise. The optimized scheme with a 5 mm opening on the pulley is used to compare and verify the aerodynamic noise simulation and testing with the original scheme without a hole on the pulley. The results show that compared with the original scheme，the optimized scheme reduces the root mean square sound pressure level of the aerodynamic noise simulation by about 4 dB，and the root mean square sound pressure level of the acceleration condition test by about 2 dB. The simulation and testing data of the original and optimized schemes are basically consistent，and the simulation method could be effectively used in engineering practice.