Using DrivAer vehicle model, the mechanism of drag reduction and noise reduction of bionic non-smooth rear-view mirror cover is studied. Wind tunnel experiments verify the validity of LES (large eddy simulation) and k - ε simulation models，and show that the rear-view mirror can increase air resistance and noise. The bionic non-smooth structure is applied to the surface of rear-view mirror cover of the DrivAer vehicle model. The simulation results show that the reasonable application of bionic non-smooth structure can reduce the resistance of the vehicle by 5.9% and the loudness outside the side window by 19.4%; The bionic non-smooth structure promotes the formation of the vortex pad effect by changing the flow state of boundary layer, which reduces the energy loss of incoming flow, improves the stability of flow field, and then has a positive impact on the aerodynamic drag and noise of the vehicle.