The　research　purpose　was　to　investigate　the　seismic　behavior　of　full-scale　square　high-strength　recycled　aggregate　concrete-filled　steel　tube　(RACFST)　columns.　With　the　recycled　coarse　aggregate　(RCA)　replacement　ratio,　shear-span　ratio　and　axial　compression　ratio　as　the　variation　parameters,　seven　column　specimens　were　subjected　to　low-frequency　cyclic　loading　tests.　The　test　results　showed　that　square　high-strength　RACFST　columns　had　reliable　seismic　performance,　their　failure　modes　were　similar　to　those　of　normal　CFST　columns,　and　the　damage　was　mainly　concentrated　at　the　column　roots.　The　bearing　capacity　and　ductility　of　high-strength　RACFST　columns　were　less　affected　by　the　RCA　replacement　ratio,　while　the　shear-span　ratio　and　axial　compression　ratio　had　a　greater　impact　on　the　peak　bearing　capacity,　ductility,　and　other　hysteretic　behavior　indexes.　Meanwhile,　a　restoring　force　model　established　based　on　the　test　research　and　theoretical　analysis　agreed　well　with　the　test　hysteresis　curves.　Finally,　a　fiber　element　model　(FEM)　using　Opensees　software　was　developed　and　a　good　agreement　was　achieved　between　the　test　and　predicated　results.　The　so-validated　numerical　model　was　then　used　to　investigate　the　influence　of　the　key　parameters,　such　as　the　RCA　replacement　ratio,　diameter-to-thickness　ratio,　axial　compression　ratio,　shear-span　ratio,　and　steel　yield　strength　on　the　seismic　performance　of　square　high-strength　RACFST　columns.