This　paper　proposed　a　novel　high-strength　steel-UHPC-clad　steel　composite　wall　(HS-UHPC-CS　composite　wall)　and　investigated　its　axial　compressive　behavior　through　experimental　and　numerical　methods.　A　total　of　18　axial　compressive　tests　and　finite　element　(FE)　analyses,　including　parametric　studies　of　120　cases,　were　conducted.　It　was　shown　that　the　stud　spacing-to-plate　thickness　ratio　and　the　normalized　slenderness　ratio　notably　affected　the　strength　and　local　buckling,　while　their　influence　on　the　initial　stiffness　was　minor.　The　strength　and　initial　stiffness　were　improved,　while　the　ductility　was　compromised　by　the　presence　of　ultra-high-performance　concrete　(UHPC).　Steel　fiber　was　critical　to　the　HS-UHPC-CS　composite　wall,　while　the　lack　of　steel　fiber　could　trigger　premature　brittle　failure.　The　influence　of　the　strength　of　concrete　was　higher　compared　to　steel　plate.　The　critical　buckling　stress　of　the　steel　plate　was　calculated　using　Euler＇s　buckling　formula　for　the　clad　steel　plate　of　the　HS-UHPC-CS　composite　wall.　The　results　were　compared　with　the　ordinary　composite　wall　database.　In　addition,　strength　from　test　results,　FE　results,　and　the　database　were　compared　were　compared　with　strength　calculated　by　design　provisions.　It　was　found　that　the　calculated　strength　was　close　but　not　safe.　It　was　recommended　that　different　concrete　contribution　coefficients　should　be　applied　for　HS-UHPC-CS　composite　walls　with　different　normalized　slenderness　ratios.　©　2024