Abstract: Based on a seven-species and six-reaction chemical kinetical mode, the real gas effects on the flow field and the aerodynamic characteristics of the Apollo return command module in a chemical nonequilibrium flow at high temperature are investigated numerically. The code presented here for the chemical non-equilibrium flow is validated through the flight data and the experimental data. Results show that the real gas effects are prominent in some regions of quite thin shock wave layers close to the wall surface, and the outstanding distance of the shock wave is reduced, and the drag coefficient and the lift coefficient are increased with the largest amplitude at a small attack angle. The real gas effect results in some additional downward force moment, moving the pressure centre backward. The larger the freestream Mach number, the greater the real gas effect on the aerodynamics of the return command module.