Simulation analysis is the basis for construction control of cable-stayed bridges, it monitors the process of the bridge construction. The relationship and importance of simulation and construction control are introduced in the paper. Based on the finite element theory and combined with construction theory of the cable -stayed bridges, according to use the software Midas/Civil, the construction characteristics of Masangxi Bridge is researched by making use of the forward calculation method and the backward calculation method. The results show that the system transformation of the bridge is occurred during the construction, thus, it is important to carry out careful and detailed forward simulation to ensure the safety of construction structure and meet with design requirements. The reasonable results can be drawn when the backward calculation method is combined with the forward calculation method.