Abstract: Through application of the 11.5 m long cantilever beam in China Jiyuan Basket-Ball City,the construction project and design method about steel-concrete-pestress large cantilever beam was depicted;the composite tension scheme combining vertical tension on the top of steel with horizontal tension to bonded string and measure ensuring structure working together was explored.It is the optimizing structural concept of the big cantilever structure,the long-span beam or the big eccentric structure or the transformation structure for the load of frequent change,and high efficiency prestressed technique is the initiative measure to guarantee the collaborating structure,steel pressure forced displacement method can give full play to the steel tensile strength and improve the anticrack and deformation performance of the structure.