Abstract:The anti-symmetric spiral pylon is used in a cable-stayed bridge scheme with the spatial, four-plane and relatively new shape. Due to the complex bridge structure, in order to select the suitable structural system, based on the stress form of bridge structure, after the comprehensive comparison of the advantages and disadvantages of floating system, semi-floating system and semi-consolidating system, the semi-floating system is determined as the preferred scheme. The reasonable constraint system of this bridge is further discussed under the earthquake action. The procedure has a certain referring value for solving the problems of reasonable structural system of similar complex structural bridges.