Combining the scientific research project- the study on cable-stayed suspension bridges, with the engineering background of Dalian Gulf Bridge to be built, this paper focuses on the seismic effect of non-linear viscous dampers on Self-anchored Cable-stayed Suspension Bridge. Based on the non-linear dynamic time-history analysis, the parameter sensitivity of damping coefficient and velocity exponent is analyzed. Through the analysis results, the proper dampers are decided. The seismic response result of before setting dampers is compared with that of after setting dampers. The results show that viscous dampers not only can greatly reduce the relative displacement and inner force under seismic effect of key positions of Self-anchored Cable-stayed Suspension Bridge, but can efficiently minimize the damage caused by earthquakes on bridge structure without changing static force behavior, which can provide evidence of seismic design for similar bridges.