Abstract: This paper introduces the application of high-frequency ultrasonic C-scan detection technique in detecting the laminated porous plate. Considering about the internal structure of the porous laminated plate and the propagation characteristics of the ultrasonic pulse reflection method, a high-frequency, small-focus focusing probe is used to obtain higher lateral resolution, and an effective evaluation of the quality of the porous laminate is achieved. Aiming at detecting smaller defects, high-resolution automated C-scanning of the welded surface of laminate porous plate is performed. It is shown that the proposed high-frequency ultrasonic testing technique is feasible and effective, and it provides an important technical means for the automatic detection of welding quality of such components.