In　highly　seismic　region,　seismic　performance　analysis　is　considered　as　an　essential　part　in　the　anti-seismic　design　of　long-span　Bridges　in　highly　seismic　region,　especially　for　the　complex　special-shaped　spatial　one.　Although　the　frame　model　has　higher　computational　efficiency,　it　cannot　reflect　the　stress　and　deformation　of　key　components.　Besides,　it　is　difficult　to　determine　boundary　conditions　of　local　members　and　simulate　the　load　transfer　process　in　an　accurate　way,　which　fails　to　meet　the　needs　of　practical　engineering.　However,　the　multi-scale　model　can　perfectly　balance　the　accuracy　and　efficiency.　This　paper,　adopted　the　multi-scale　model　and　frame　model,　researches　the　dynamic　characteristics　of　long-span　space　Y-shaped　arch　bridge,　which　verifies　the　accuracy　and　reliability　of　employing　the　method　of　multi-scale　model　in　the　research.　Besides,　except　for　the　analysis　of　the　seismic　response　law,　this　study　also　discusses　the　stress　and　deformation　characteristics　of　key　components　of　long-span　space　Y-shaped　arch　bridge　and　evaluate　the　anti-seismic　performance　of　the　bridge　on　the　whole.　©　2023　Science　and　Technology　Periodical　Press.　All　rights　reserved.