Considering that earthquakes occur frequently in China,four vertical and four horizontal high-speed railway networks are planned,and 23 provincial capital cities and two-thirds of the cities with populations of more than a million are located in regions of high seismic intensity,seismic design is the controlling factor in the design of high-speed railway bridges.The differences between a high-speed railway bridge and a highway or common railway bridge lie in the following aspects： First,pier,bearing system,and displacement restrictions are required to strictly ensure that high-speed trains remain on the rails.Second,bridges make up a large proportion of the high-speed railway,and most of these bridges are viaducts and long.Third,the high-speed railway will have a major impact,being traffic intensive,high speed,high cost,and so on.Fourth,gravity piers（or hollow piers） are generally used in the substructures of such bridges,and these piers often have large section size and low reinforcement ratio.The long-span continuous bridge is the most widely used bridge type in Chinese high-speed railway construction,and the structural form of ＂multiple spans as one unit＂ is often used in this bridge type,with only one fixed pier per unit.Under earthquake force,the inertial force of the superstructure is mainly exerted on the fixed pier,so the fixed pier must meet the requirements of strength and ductility.For this reason,most fixed piers of long-span continuous bridges are reinforced concrete gravity piers.Under frequent earthquake action,piers are required to be elastic,and strength failure criterion can be used to check piers.Under rare earthquake action,because a pier would be in a plastic state,the deformation failure criteria would be used.The seismic checking index for each level is combined with the three-level seismic fortification goal based on the structural characteristics of a long-span continuous beam high-speed rail bridge.A seismic response analysis was performed on an actual bridge by use of a response spectrum method,and elasto-plastic history response analysis and seismic performance evaluation were also conducted.The results showed that the seismic design of the bridge was controlled by the fixed pier.The fixed pier is in an elastic state under low-level earthquake conditions.Under high-level earthquake conditions,however,it enters a plastic state in the longitudinal direction,but the displacement ductility factor is less than the allowable value so it has sufficient ductility capability in reserve.Therefore,the seismic capacity of the bridge meets the three-level seismic fortification goal.