The invention relates to the technical field of cable-stayed bridges, in particular to a railway large-span cable-stayed bridge rigidity control method and a cable-stayed bridge. The railway large-span cable-stayed bridge rigidity control method disclosed by the invention can analyze effect laws of structural rigidity parameters of the cable-stayed bridge on three aspects of bridge dynamic property, vehicle dynamic response and bridge dynamic response by establishing a dynamic analysis model and utilizing a dynamic analysis method. Meanwhile, the control method utilizes a vehicle-bridge system evaluation index system as indexes to judge to obtain a rigidity limit value range and a design parameter value range of the railway large-span cable-stayed bridge, so that rigidity and design parameters of the designed railway large-span cable-stayed bridge are in the limit ranges, the rigidity is controlled, the large-span cable-stayed bridge can meet a requirement for use performance, an important effect for popularizing the railway large-span cable-stayed bridge is achieved, and enormous cost is saved.