To obtain the aerodynamic forces accurately and provide theoretic guide for the design of missile's configurations, a numerical simulation of the flow fields around an actual configuration of air-to-air missiles (AAM) is performed by solving the Reynolds averaged Navier-Stokes equations (RANS). The Spalart-Allmaras（S-A） one equation turbulence model is coupled to close the governing equations. The Jameson's finite volume multistage Rung-Kutta time-stepping scheme and spatial central difference coupled with artificial viscous terms are used in the computation. A patched multi-block structured grid is generated around the complex configuration using the multi-zone technique and elliptic partial differential equations. The simulations are conducted in supersonic flow at different angles of attack. Aerodynamic forces and moments acting on the body, rudders and ailerons of the AAM with or without angle of roll are calculated. These results agree well with the experiment and those using other codes, and they show that the scheme can be adopted in the computations of the complex flow fields around actual configuration of multi-wing missiles.