Abstract: In the past few years, with the development of marine oil, the weight of the offshore oil module has been increasing gradually, and the deck is an important part of the module. As the weight of deck increases, the weight and size of single deck also increases. Because of the large weight of single slice and the ability to exceed the lifting capacity, one deck must be divided into several pieces to lifting and hoisting separately. In the process of high-altitude group alignment, the set of closing positions becomes a difficult point. This paper introduces how to divide the deck pieces and choose the location of the space assembling to converts complex nodes at the closure to simple nodes, and strengthen check is also made.