Abstract: Analyzed the aerodynamic characteristics through simulation of different treatment methods of car modeling,placement of engine,ground clearance and the removal mode of the cooling air in engine cabin with FLUENT software.The results show that: adding the wheels has the greatest impact on the aerodynamic characteristics,there is a best place for engine,and different ground clearances have great impact on the result of simulation.So,selecting the removal mode of the cooling air in engine cabin has to consider both the drag coefficient and lift coefficient.