Abstract: Concrete filled steel tubular arc-cable combined bridge is a new bridge type, whose structural system is adjustable. In view of its structural differences during construction range and finished state, the zero moment method and the influence matrix-based optimal method were used to find the rational pre-tension forces in soft cables. The zero moment method assumes zero moment is developed at the interface of adjoining segments under dead load. The influence matrix-based optimal method uses the longitudinal moment distribution under dead load as an objective function and the pre-tension forces in cables as optimized variables, and then determines the section moment resulting from the cable tension with the help of influence matrix. At last, taking Tian Zishan bridge as an example, the feasibility of the method is verified.