Abstract: The discrepancy of nondestructive test technology of nuclear island main equipment at the stage of manufacturing and PSI (Pre-Service Inspection) was analyzed and researched in order to provide the recommendatory processing method and reference for additional testing in the manufacturing stage according to the requirements of PSI.The other aim of this study was to promote manufactory to perform relative testing and to effectively avoid potential risks in quality and schedule caused by nondestructive testing technology difference during manufacturing and PSI stages.