Abstract: A method including equilibrium gas effects have been given to generate waveriders fling at high altitude with high Mach number. And the CFD technique has been used to investigate the equilibrium gas effects on aerodynamic and aerothermal characteristics of waveriders fling at high altitude with high Mach number. The results indicated that the equilibrium gas affects aerodynamic characteristics of waveriders slightly in comparison with perfect gas, but it does have some effects on the aerothermal characteristics of the nose region and lower wall for wavriders. Additionally, the angle of attack, which is suitable for waverider, will not change the equilibrium gas effects on aerodynamic of waveriders and heat flux and radiative equilibrium temperature of nose region of waveriders, but it will narrow the region affected by equilibrium gas of heat flux and radiative equilibrium temperature down for lower wall of waveriders.