Abstract: The characteristics and theory of combination of pulse-echo (PE) and time of flight diffraction (TOFD) techniques are shown in this paper. The application of this combination in circumferential butt weld inspection is introduced either. Compared with the inspecting results of some other inspection methods to the same preset defects, present defect evaluation is more reasonable with higher inspection efficiency and lower labor intensity. The combination of PE and TOFD techniques is not only quite valuable for product quality control in a more economical and reliable way, but also is guaranteed to defect inspection rate and detection effect.