Cable-stayed bridge is a kind of high time for the hyperstatic structure,each construction segment is very complex,especially to the prestressed concrete cable-stayed bridge.In construction state,the strength of cable force,is not only related to the the security,the internal forces and deformations of structure,but also to the safety of operation stage.According to the construction order,Iterative method is used forward to optimize the construction cable force,so that to achieve the goal of bridge state.