Based on the wind tunnel test data of aerodynamic performance of MIRA vehicle body, the iteration step, time step, and grid scheme were researched when large eddy simulation was adopt to solve the obviously transient flow field with large separation structure around bluff body near ground. Meanwhile, the simulation accuracy of three subgrid scale turbulence models was studied using the comparative analysis method. Finally, the solving strategy of large eddy simulation was proposed which is applicable for the simulation of aerodynamic performance of notchback vehicle.