The traditional numerical simulation of fluid mechanics does not consider the interaction between the elastic structure of the car body and the external flow field，which makes the results inconsistent with the real situa? tion. Taking a real vehicle model as the research object，the CFD simulation considering the effect of fluid-structure interaction is carried out，and the results of aerodynamic drag，aerodynamic lift，flow field structure and other as? pects are compared with the traditional fluid numerical simulation results. The results show that the fluid-solid cou? pling effect has a greater impact on the aerodynamic lift，and the difference between the two simulation methods can reach 38% with the increase of vehicle speed，which is directly related to vehicle stability and safety. Using fluidstructure coupling CFD numerical simulation to explore the characteristics of wind-induced vibration of the whole ve? hicle，it is proved that the main influencing factors of the actual vehicle vibration amplitude are the wind-induced vi? bration frequency and the magnitude of the force. Moreover，the stiffness of the vehicle elastic structure is optimized to improve the wind-induced vibration of the vehicle，so as to improve the comfort of passengers.