The seismic isolation of combined system of continuous girder-arch railway bridge is studied with friction pendulum bearing（FPB）.Based on the characteristics of the system,the design principles and methods for seismic isolation of combined system using FPB is proposed.The nonlinear time history analysis method is used for the analysis of isolation effect.The results show the maximum seismic moment and deformation of the vault can be significantly reduced by using FPB in longitudinal direction.The reduction of isolation is greatly influenced by input ground motion in transverse direction.