Abstract: The comprehensive gymnasium of the Ocean University of China is a hyperbolic paraboloid steel grid structure constructed for the 11th National Basketball Games. It is one of the key construction projects in Qingdao. To develop the installation scheme, the characteristics of the structure and construction site were considered, and a new construction method which is cantilever extended assembly technology with a strip-type support frame was used for the grid structure to avoid the erection of full hall scaffold effects on lower construction. The stability factor of starting elements, cantilever expansion sequence and the size of the element were analyzed by using ANSYS softwares. The stability requirement of the starting unit, sequence of expansion and the number of the expanding units were put forward for the structure in this construction method.