In order to determine the reasonable lateral seismic constraint system of cable-stayed bridge under strong earthquake, the nonlinear time history analysis method was used to analyze the seismic responses of long-span bridge with four lateral connection systems based on the Ke-Ke-da-la bridge . The impact of four constraint systems including transverse sliding system,fixed system,and seismic isolation system adding displacement dependent and velocity-related type on the yield load of steel dampers and the viscous dam-per position and relevant parameters were investigated and the seismic responses were compared with other systems. The results indicated that ,for large span bridge, the transverse sliding system and whole limit system were not ideal seismic system under the action of earthquake; seismic isolation device could significantly reduce the bottom of the pier and the tower seismic shear force and bending moment.However, in typical circumstance, transverse steel damping device was superior to the viscous dampers between tower and beam.