This　paper　experimentally　and　numerically　investigates　the　shear　behavior　of　high-strength　square　concrete-filled　steel　tube　(HS-SCFST)　members.　A　total　of　20　specimens　were　first　tested.　The　test　parameters　were　the　shear　span-to-depth　ratio,　width-to-thickness　ratio　of　the　steel　tube　wall,　yield　stress　of　steel,　and　compressive　strength　of　concrete.　Detailed　finite　element　(FE)　models　were　then　developed　and　benchmarked.　The　benchmarked　models　were　then　used　to　conduct　a　total　of　87　parametric　studies.　It　was　shown　that　(i)　the　shear　strength　and　stiffness　increased　with　decreasing　shear　span-to-depth　ratio　or　width-to-thickness　ratio,　and　(ii)　the　increase　in　yield　stress　of　steel　and　compressive　strength　of　concrete　improved　the　shear　strength,　but　had　a　minor　effect　on　the　stiffness.　Results　from　the　experimental　tests　and　finite　element　analyses　were　also　used　to　evaluate　the　applicability　of　several　international　design　provisions　(e.g.,　AASHTO　BDS,　Eurocode　4,　WSDOT　BDM　and　CECS　28)　for　estimating　the　shear　strength　of　HS-SCFST　members.　It　was　shown　that　CECS　28　provided　the　most　reasonable　estimation　of　the　shear　strength,　but　the　contribution　of　steel　tube　and　concrete　infill　was　not　accurately　calculated.　A　new　design　equation　was　therefore　proposed,　considering　the　effect　of　shear　span-to-depth　ratio　and　the　contribution　of　the　steel　tube　and　concrete　infill.　©　2022　Elsevier　Ltd