A suspension bridge is more appropriate type of structure for extremely long-span bridges due to the rational use of structural materials. Increased deformability, which is conditioned by the appearance of the elastic and kinematic displacements, is the major disadvantage of suspension bridges. Prestressing can solve the problem of increased kinematic displacements under the action of nonsymmetrical load. A prestressed suspension bridge with the spans of 50, 200 and 350 m was considered as the object of investigation. The cable truss with the cross web was considered as the main load carrying structure of the prestressed suspension bridge. Optimization of the cable truss web by 9 variables was realized using genetic algorithm. It was obtained, that the displacements of the prestressed suspension bridge with the proposed cable truss are smaller by 26–30% than the displacements of the structure with the single main cable for the span interval from 50 to 350 m in the case of the worst situated load.