The hysteric-friction isolation system with elastic-plastic displacement-constraint device is put forward. The action mechanism and restoring force model of the elastic-plastic displacement-constraint device are analyzed. The nonlinear seismic responses of structures supported on Hysteric-friction isolation system with elastic-plastic displacement-constraint device under main shock and aftershock are researched. The results indicate: the displacement-constraint device not only can ensure the upper structure safety, but also can effectively limit the displacement of the isolation layer, meanwhile can supply secondary protection under strong aftershock. The structure of the device is simply, which is convenient for production and installation. Meanwhile because the device is cheap, it can be widely used in isolation building.