In order to research the dynamic performance of a railway bridge with bidirectional lead rubber seismic isolation bearings under train load,a three spans bridge was established with ANSYS. The coupling vibration mechanism was studied between bridge and train. The results show that, the transverse displacement increases with the isolation period of transverse increase. The bearing damp attenuates the horizontal vibration and has little action on the tensional and vertical displacement. The transverse wiggle, side rolling and vertical displacement change little with the transverse seismic period increase. The bearing damping has little influence on the transverse wiggle, side rolling angle, shaking angle, up and down displacement, nodding angle displacement and acceleration response of each degree of freedom.