Shaking　table　test　is　an　effective　means　to　study　the　complex　dynamic　characteristics　and　seismic　response　of　large　structures,　and　it　is　the　key　to　desigh　the　scale　model　structure　in　the　shaking　table　test　due　to　the　limitation　of　shaker　size　and　load.　Based　on　the　dimensional　similarity　method　and　elastic　similarity　law,　the　geometric　similarity　ratio　of　1:　20　was　taken,　and　the　design　of　the　dynamic　scale　model　of　key　parameters　was　carried　out　using　a　spatial　special-shaped　arch　bridge　as　the　prototype.　Firstly,　through　finite　element　numerical　analysis,　the　dynamic　characteristics,　internal　forces　and　displacements　of　the　original　bridge　model　and　the　scaled　bridge　model　under　dynamic　action　are　analyzed　to　verify　the　rationality　of　the　scaled　model.　Under　the　selection　of　reasonable　seismic　action,　the　structural　time　history　response　analysis　was　carried　out.　The　calculation　results　show　that　the　scaled　model　bridge　is　completely　consistent　with　the　first　tenth-order　mode　of　the　prototype　bridge　with　the　frequency　error　less　than　7%,　the　response　error　of　internal　force,　displacement　and　acceleration　of　the　key　section　has　not　exceeded　10%,　and　the　scaled　model　bridge　can　reflect　the　dynamic　characteristics　and　response　characteristics　of　the　original　bridge.　This　research　work　can　provide　technical　support　for　the　seismic　design　of　shaking　table　of　space　irregular　arch　bridge,　and　provide　reference　for　shaking　table　tests　of　similar　bridges.　©　2024　Editorial　office　of　Earthquake　Engineering　and　Engineering　Dynamics.　All　rights　reserved.