This　paper　compiled　an　experimental　database　consisting　of　320　square　concrete-filled　steel　tube　(CFT)　beam-columns　subjected　to　cyclic　loading.　Approximately　82　%　of　these　specimens　were　conventional-strength　CFTs,　revealing　a　significant　lack　of　test　data　for　high-strength　CFTs.　According　to　the　current　AISC　Specification　(AISC　360–16),　CFTs　are　classified　into　three　categories　based　on　the　width-to-thickness　ratio　(b/t):　compact,　noncompact,　and　slender　sections.　Notably,　there　is　a　gap　in　research　regarding　the　seismic　behavior　of　noncompact　and　slender　CFTs.　To　address　this　gap,　detailed　finite　element　(FE)　models　were　developed　and　validated.　Based　on　the　benchmarked　model,　an　additional　156　high-strength　concrete-filled　high-strength　steel　(HS-HC)　models　were　introduced　to　supplement　data　for　high-strength　square　concrete-filled　steel　tube　(HS-SCFT)　members　with　slender　and　noncompact　sections.　Combined　with　the　experimental　database　and　the　FE　analysis,　the　calculation　method　for　the　strength　of　HS-SCFT　beam-columns　as　outlined　in　AISC　360–16　and　GB50936　was　evaluated.　The　results　indicated　that　the　axial　load　(N)　calculated　according　to　GB50936　was　more　conservative　for　compact　sections,　whereas　the　N　calculated　using　AISC　360–16　was　more　conservative　for　slender　sections.　Additionally,　the　flexural　strength　(M)　calculated　using　AISC　360–16　demonstrated　the　best　agreement　with　experimental　results,　while　the　M　calculations　from　GB50936　exhibited　greater　dispersion.　A　new　simplified　method　for　calculating　the　load-displacement　skeleton　curve　of　HS-SCFT　beam-columns　was　proposed　considering　the　effect　of　critical　parameters.　The　findings　indicated　that　the　proposed　method　effectively　captures　the　behavior　of　HS-SCFT　beam-columns　under　cyclic　loading.　©　2025　Institution　of　Structural　Engineers