In view of weld Non-Destructive Testing (NDT) in ocean engineering project, an automatic sampling system is designed. The weld testing standards are proposed, the system design elements such as weld grade, sampling method, and sampling proportion are sorted out, and the system composition such as functional structure, basic setting plate, and sampling length plate are determined. The practical application results show that the system can realize the full coverage function of electronic flow of weld NDT sampling list.