Abstract: The detecting capability of infrared thermal wave nondestructive testing technique has attracted much attention. In general, the detecting capability is referred to the detected defects minimum size and maximum depth in some specific material. The experimental results of pulse heating thermal wave nondestructive testing technique of fiber glass material is shown, which is widely used in aviation and aerospace and so on. The sample is excavated six identical flume defects at different depth. The design can reflect the linear change of the width and the depth of the defects. The optimum condition for the detecting capability such as heating energy and infrared camera capture frequency is discussed.