Considering nonlinear aerodynamic forces and airfoil structure nonlinearity, aeroelasticity of supersonic airfoil was researched. Using the bifurcation diagram, phase diagram and Poincare map，effect of airfoil aeroelasticity by nonlinear aerodynamic forces and parameters of structural hysteresis was analyzed. Research shows that only consider nonlinear aerodynamic force, systematic motion tends to periodic and quasi- periodic LCO movement, and the vibration amplitude of plunge and pitch movement leap with Ma increasing .When taking into account the nonlinear aerodynamic force and structural nonlinearity, with the change of damping factor, the system will appear subcritical and supercritical flutter, and for the influence of nonlinear structure, movement leap of vibration amplitude does not occur. This means the choice of reasonable structure parameters will help to improve the aeroelastic characteristics of airfoil.
