This paper discussed the following problems,such as computing meshing definition, simulation precision, modeling efficiency and design methods of the subdivision mesh model used in automobile flow field simulation.The wind tunnel test of an aerodynamics ideal model was taken as an example. It comes to that the simulation precision of subdivision mesh model after improving surface features is as good as NURBS model, at the same time it has the advantage of high modeling efficiency and unrestricted modification,in the design processes if it can be combined together with NURBS model, then the requests on both conception and engineering can be fulfilled. 