The failure behavior and the vulnerable position of the rigid frame bridge are analyzed by nonlinear response analysis, based on incremental dynamic analysis (IDA). The damage index, applying for long-span continuous rigid frame bridge with high pier, is studied. The seismic vulnerability problem of the whole bridge is analyzed by fiber model. The strain was used for damage index of piers. The displacement was used for damage index of bearings. According to the studies above, the fragility curves are established based on integral performance of the bridge.