The analysis approach of semi-active control for long-span rigid-continuous bridge under seismic travelling wave input is established. Magnetorheological dampers are set on the positions of the bridge bearings. The semi-active control calculation and analysis are performed for a five-span rigid-continuous bridge under seismic travelling waves with different apparent surface velocities. The results indicate that travelling wave effect remarkably influ- ences the uncontrolled seismic responses, the semi-active control seismic responses and vibration control effects for the long-span rigid-continuous bridge. It is disadvantageous to the responses of the beams and the piers under the travelling wave input with lower apparent surface velocity, and travelling wave effect can decrease the vibra- tion control effects evidently. Therefore, the travelling wave effect should be considered for the selection of the parameter values of semi-active control system in order to get the designing control effect. The analysis approach of semi-active control for long-span rigid-continuous bridge under seismic traveling wave input is established. Magnetorheological dampers are set on the positions of the bridge bearings. The semi-active control calculation and analysis are performed for a five- span rigid-continuous bridge under seismic traveling waves with seismic apparent effects and vibration control effects for the long-span rigid-continuous bridge. It is disadvantageous to the responses of the beams and the piers under the traveling wave input with lower apparent surface velocity, and traveling wave effect can decrease the vibra- tion control effects evidently. Therefore, the traveling wave effect should be considered for the selection of the parameter values ​​of semi-active control system in order to get the designing control effect.