Abstract: For understanding the geometry of the joint, controlling the quality of the clinched joint, checking the internal characteristic of the clinched joint and the mechanical characteristic, and finding the internal failure of the clinched joint, it is an important task for the nondestructive testing technology to check quality of the clinched joint. In this paper, nondestructive testing technology (color penetrant detection, induction thermal imaging detection, active thermal imaging detection, X-ray examination, visually nondestructive testing, etc) was used to check the groove of the clinched joint, the control system of quality for the surface and internal of the clinched joint and the defect expert system was built.