Icing is a prominent problem in flight! The aerodynamic shape of the aircraft will change a lot after the icing.Thus aircraft performance, maneuvering capability and stability will become worse.Icing will be a great threat to the flight safety.How to assess and predict the aerodynamic characteristics of aircraft after the icing is a critical technical problem in the general design of the modern airplanes especially the civil airplane.At the same time.it is the important foundation in the design of flight control system with aircraft icing avoidance technique.