Steel　bridge　piers　are　typically　considered　to　have　good　seismic　performance　and　ductility.　However,　long-term　exposure　to　atmospheric　environment　can　lead　to　corrosion　of　the　steel　bridge　piers,　which　may　lead　to　different　performance　and　failure　modes　throughout　life-cycle　stages.　This　study　aims　to　explore　the　time-varying　seismic　performance　evolution　of　steel　bridge　piers　in　different　atmospheric　environments　and　propose　a　time-varying　seismic　evaluation　method　based　on　performance　requirements.　First,　a　numerical　simulation　method　for　aging　steel　bridge　piers　is　developed　by　considering　the　time-varying　model　of　corrosion　characteristic　parameters.　The　degradation　patterns　and　failure　modes　of　steel　bridge　piers　with　varying　parameters　throughout　their　entire　life-cycle　in　industrial　and　marine　atmospheric　environments　are　then　analyzed.　The　concept　of　timevarying　degradation　ratio　and　aging　damage　index　is　used　to　quantify　the　effects　of　time-varying　factors　on　seismic　performance.　Finally,　formulas　for　predicting　critical　displacement　values　based　on　performance　requirements　are　established,　and　a　time-varying　seismic　performance　evaluation　method　and　process　are　presented.　The　results　show　that　the　seismic　performance　degradation　of　aging　steel　bridge　piers　caused　by　different　service　environments　can　reach　up　to　23.7　%.　In　addition,　in　the　early　stages　of　service,　seismic　performance　of　aging　steel　piers　may　be　significantly　reduced,　with　the　displacement　ratio　for　safety　performance　points　decreasing　by　up　to　28.6　%.　Corrosion　leads　to　more　pronounced　plastic　deformation　and　stress　concentration　in　the　failure　mode　of　aging　steel　piers.　The　aging　damage　index　is　affected　by　the　coupling　of　corrosion　parameters　and　geometric　parameters.　As　service　time　progresses,　the　value　and　variability　of　aging　damage　index　of　steel　piers　increase.　The　accuracy　of　the　formula　for　predicting　time-varying　critical　displacement　values,　considering　performance　requirements,　is　validated　through　supplementary　models　and　previous　test　results.　The　results　underscore　the　importance　of　considering　aging　effect　and　environmental　factors　in　the　seismic　performance　evaluation.　The　proposed　time-varying　seismic　performance　evaluation　method　can　provide　reference　for　the　lifecycle　seismic　design　and　verification　of　aging　steel　bridges.