Abstract: It is very important to detect the defects of composite materials. In this paper, the principle of infrared thermal wave imaging technology is introduced, and the pulse infrared thermal wave imaging technology and lock-in infrared thermal wave imaging technology are focused on. The two technologies are used to detect a variety of composite materials. The experimental results show that pulsed infrared thermal imaging technology and lock-in infrared thermal imaging technology are rather effective in the detection of composite material defects.