Abstract: Corrosion of lap joint structure directly endangers the life and structural strength of the aircraft, and the safety of flight. For corrosion is in the highly hidden locations, conventional nondestructive inspection is not satisfactory. Through the establishment of the aircraft lap joint structure model, using ANSYS software to simulate the testing environment, the surface temperature distribution is calculated and the surface heat characters can be known by finite element analysis in the paper. The emphasis is placed on testing the feasibility of infrared NDI from the corroded area, corrosion depth, surface scratches, and thus providing a theoretical basis of using infrared NDI to inspect lap joint structure.