Abstract: After the steam generator anti-vibration bar assembly is installed and welded, the positions of some anti-vibration bars and heat transfer tubes cannot be directly measured. In this paper, through the actual simulation of the lap between the heat transfer tube and the anti-vibration bar, different lap positions of the anti-vibration bar were selected in different bend radii, and the lap signal was measured by eddy current test method. The relationship and rule between the eddy current signal and the lap depth were analyzed, which could be used to evaluate the lap condition of the heat transfer tube and the anti-vibration bar of the product.