Abstract: In this paper, the simulated test plates with thickness of 10 mm and 30 mm and containing eight kinds of welding defects, such as porosity, strip, tungsten inclusion, incomplete fusion, incomplete penetration and crack are tested by TOFD technique. Comparing the experimental results with the radiographic testing, it is found that the nine kinds of defects can be detected, which proves that the technology is reliable in aluminum alloy welding seam nondestructive testing, and it is hoped to promote the application of this technology in the weld inspection of aluminum pressure equipment.