This　study　investigates　the　cyclic　behavior　of　high-strength　square　concrete-filled　steel　tube　(HS-SCFST)　beamcolumns　through　experimental　testing　of　9　specimens　and　complementary　finite　element　analysis.　The　specimens　were　subjected　to　constant　axial　load　and　cyclic　flexural　loading,　with　test　parameters　including　axial　compression　ratio,　steel　yield　stress,　concrete　compressive　strength,　and　width-to-thickness　ratio.　The　finite　element　models　were　benchmarked　for　parametric　studies.　The　results　showed　the　axial　compression　ratio　influenced　ultimate　strength　and　envelope　curve　shape,　while　increased　steel/concrete　strength　improved　strength　and　energy　dissipation　capacity.　However,　higher　slenderness　and　width-to-thickness　ratios　decreased　strength,　ductility,　and　stiffness　notably.　Evaluation　of　building　codes　GB50936,　EC4,　AISC360-16,　and　AIJ　showed　EC4　was　most　reasonable,　GB50936　most　conservative　as　it　neglects　stress　distribution　between　steel　and　concrete,　and　AISC　360-16　conservative　as　it　excludes　concrete　contribution.　The　study　indicates　existing　code　provisions　need　improvement　for　calculating　HS-SCFST　member　strength.　Additionally,　a　simplified　calculation　model　was　proposed　to　determine　envelope　curves　for　HS-SCFST　beam-columns　based　on　the　experimental　and　FE　results.　In　summary,　the　study　provided　data　on　HS-SCFST　cyclic　behavior　and　code　evaluations,　proposing　enhancements　for　design.