Abstract: A new modelling and simulation method for flexible wing aircraft was presented to describe coupling effects between rigid-body movement and structure deflection. Rigid-body movements and structural deflections were calculated under independent inertial and non-inertial systems respectively. Aerodynamic forces and inertial forces were used to describe the rigid flexible coupling dynamic properties. The mathematical solution was to calculate forces, rigid-body movements and elastic deflections in a specific order inside a time-step, and a cyclic solving method was used between time-steps. Simulation results of aircraft's attitude dynamic response were used to check the reliability of this method. The results confirm that this modelling and simulation method is able to represent dynamic characters of flexible wing aircraft.