Abstract: Existing piston theory for supersonic flow can only deal with thin supersonic wing with sharp leading edge at small angles of attack. The unsteady CFD technology basing on Euler/N-S equations can solve the unsteady aerodynamic loads precisely, but it often needs much computational time even just for a simple 3D shapes. Local piston theory basing on steady CFD technology has a good precision and high efficiency to compute the supersonic or hypersonic unsteady pressure by comparing the piston theory and unsteady Euler code. Coupling the structure equations, the supersonic or hypersonic aeroelasticity is simulated in time domain. The computed flutter precision of local piston theory is higher than original piston theory by comparing with the experimental data. The non-linear characteristics of the flutter speed with increasing Mach number and increasing anger of attack of a typical wing are studied. The computed flutter results by local piston theory agree with the theoretic analysis and are better than original piston theory at high Ma numbers.