Method for improving aerodynamic performance of vehicle

The invention relates to the field of vehicle endurance and passenger vehicle design and manufacture, and discloses a method for improving vehicle aerodynamic performance, which comprises the following steps: S1, designing a guide plate, and respectively establishing a vehicle model and a guide plate model based on vehicle model data and guide plate data; s2, combining the whole vehicle model and the guide plate model, and dividing a surface mesh of the combined calculation model and a volume mesh with an encrypted domain; s3, whole vehicle three-dimensional flow field simulation calculation is carried out on the combined model, steady-state calculation is adopted in simulation calculation to obtain flow field distribution data and flow field result analysis of a flow guide plate area located at a rear auxiliary frame of the vehicle, and whole vehicle wind resistance performance evaluation is carried out; and S4, changing the parameters of the guide plate model, then respectively carrying out operations from