Abstract: A new type of damper called metal alloy brace with plump hysteresis loops and strong dissipation energy capability is recommended.Within the designed displacement the output force is stable and small,while the output force can increase greatly when the designed displacement is exceeded.The FE model of a viaduct has been established to analyze the implication of the metal alloy brace on seismic control and make comparison with the traditional restrainers.The results show that the damper can provide more than 40 percent of passive energy dissipation ratio under the seismic excitation of design intensity,which can inhibit the elastic hinge and restrain the bearing displacement.When the designed intensity rises,the metal alloy brace can protect the bridge not only by dissipating energy,but also by restraining the displacement to avoid girder's falling and collision.Restrainers can also effectively prevent the falling-off of the girder,but may enlarge the shear force at the piers and fixed bearings.So the metal alloy brace can replace the restrainers because it can ultimately protect each component of the bridge from destroying.