The　pier　ends　of　high-pier　bridges　are　prone　to　serious　damage　and　the　significant　plastic　hinge　can　occur　when　the　bridge　is　subjected　to　rare　earthquake.Furthermore,　the　damage　degrees　of　each　pier　are　different.If　one　single　pier　is　seriously　damaged,　the　integral　failure　of　the　bridge　can　occur,　so　the　overall　seismic　capacity　of　bridge　is　not　adequately　fulfilled.In　order　to　optimize　the　seismic　performance　of　bridges,　the　concept　on　uniform　damage　design　of　bridges　is　proposed.Since　the　damage　index　based　on　elastic-plastic　energy　dissipation　difference　can　accurately　characterize　the　seismic　damage　evolution　process,　it　can　be　used　as　a　quantitative　damage　assessment　index.In　view　of　the　limitations　of　the　existing　plastic　hinge　length　in　damage　assessment,　the　concept　and　calculation　method　of　the　time-varying　plastic　hinge　length　of　single　pier　and　double　pier　are　proposed.Finally,　the　uniform　damage　oriented　optimal　design　process　of　bridge　considering　seismic　fragility　is　proposed.Taking　a　continuous　rigid　frame　bridge　with　unequal　high　piers　as　an　example,　the　seismic　optimization　design　and　analysis　for　uniform　damage　are　carried　out.For　the　original　design　scheme,　the　normal　improvement　scheme　and　the　uniform　damage　optimization　scheme,　the　damage　index　at　the　plastic　hinge,　the　displacement　at　the　top　of　the　piers,　the　energy　dissipation　at　the　bottom　of　the　piers,　the　length　of　the　time-varying　plastic　hinge　and　the　seismic　fragility　analysis　are　used　to　carry　out　an　intensive　comparison　and　analysis.　The　results　show　that　the　uniform　damage　optimization　scheme　can　enhance　the　performance　of　each　index.　The　uniform　damage　oriented　bridge　optimization　design　can　significantly　improve　the　damage　state　and　the　integral　seismic　performance　of　the　bridge.　©　2021,　The　Editorial　Board　of　Journal　of　Basic　Science　and　Engineering.　All　right　reserved.