Abstract: Based on adaptive overlapped grid system, a transonic flow around delta wing with blunt leading edge was simulated by solving the Navier-Stokes equations. The ability of this grid system in capturing the flow field details was observed at different angles of attack and transonic inflow conditions. A body-fitted grid block was used to accurately describe the delta wing configuration, and an adaptive overlapped grid was adopted for the vortex evolution and the shock/vortex interaction. The Spalart-Allmaras (SA) turbulence model and the corresponding Detached Eddy Simulation (DES) method were used for the eddy viscosity estimation. The SA model results were compared with those of the DES at different angles of attack and Mach 0.85. Better results were obtained by the DES method with high angle of attack due to its capability of capturing massive separations. The grid generation in this system is relatively inexpensive, and the simulation results based on this grid system are numerically accurate. The present methods are suitable for delta wing shock/vortex interaction simulation.