The invention discloses a rigidity and viscosity combined restraint structure and method, which are applied to a restraint system of a cable-stayed bridge. The cable-stayed bridge comprises a first main tower and a second main tower. The rigidity and viscosity combined restraint structure comprises a rigid restraint device supporting one end of the cable-stayed bridge and a combined restraint device supporting the other end of the cable-stayed bridge, wherein the rigid restraint device comprises a rigid support and a rigid substrate; the rigid support is arranged above the rigid substrate, and the rigid substrate is arranged on the first main tower; the combined restraint device comprises a vertical restraint device and a viscosity restraint device, wherein the vertical restraint device comprises a vertical support and a vertical substrate; the vertical support is arranged above the vertical substrate, and the vertical substrate is arranged on the second main tower; the viscosity restraint device comprises a viscosity restraint substrate arranged on the second main tower; a fixing component is arranged on the viscosity restraint substrate; a moving component is also connected between the vertical restraint device and the fixing component; and the moving component is arranged in the axle direction. Through the adoption of the rigidity and viscosity combined restraint structure and method disclosed by the invention, the static and dynamic performance of a bridge can be improved, the operation safety and comfort of trains can be guaranteed, and the design and construction economy of the bridge is increased.