Abstract:The Infrared Thermography is a fast and effective NDT technology which developed ten of years. The non-uniform structure under the surface becomes visualized because of the surface temperature variation by the active heat stimulation; and the locating,recognition and quantitative measurement of the defects are realized by data processing. Infrared thermography NDT is an interdisciplinary technology; the research and application of it improve the safety and reliability of variety of military and civilian equipment. In this paper,the principle,concept and system compositions of infrared thermography are briefly introduced; technical characteristics of several stimulations methods,such as light pulse,ultrasonic,Lock-in,and THz are compared and analyzed; furthermore,development of the technology at aboard and native is introduced,as well as some typical applications are shown,and finally the development trend of this technology is summarized.