Abstract: Taking the steel lining penetration sleeves of the “Hualong No.1” nuclear island in Taipingling, Huizhou as the testing object, this paper introduces the key points and common defects of visual inspection in each stage of prefabrication, focused on the measurement of longitudinal weld seam excess height and misalignment in the sleeve section, proposed a correction calculation method and correction formula for the measurement deviation of longitudinal weld seam excess height in the inner and outer sides of the sleeve section, and verified it using macroscopic metallographic corrosion results, Finally, a practical measurement method for misalignment was proposed and its feasibility was verified, aiming to ensure that visual inspection during the prefabrication process of penetration sleeves met relevant standard requirements,provide some references for the inspection of steel containment penetrations in nuclear power plants.