Focusing　on　special-shaped　bifurcated　concrete-filled　steel　tube　(CFT)　column　with　multiple　cavities　of　mega-frame　structures　in　super　high-rise　buildings,　in　order　to　investigate　the　influence　of　cross-sectional　enhanced　structures　on　the　seismic　behavior　of　the　bifurcated　short　column,　four　specimens　subjected　to　vertical　axial　load　and　horizontal　twice　loaded　cyclic　loading　were　tested.　The　upper　part　of　the　specimen　includes　two　pentagonal　CFT　column　branch　with　four　cavities,　while　the　lower　part　includes　one　octagonal　CFT　column　branch　with　13　cavities.　As　a　result,　a　bifurcated　column　was　formed.　The　investigated　cross-sectional　structures　weredivided　into　four　types:　basic　type,　the　type　that　the　thickness　of　the　whole　tube　steel　plate　is　increased,　the　type　that　the　thickness　of　local　steel　plate　being　far　from　the　neutral　axis　is　increased　by　welding　steel　angle,　and　the　type　that　circular　steel　tube　is　encased　in　the　cavities　being　far　from　the　neutral　axis.　Based　on　the　test　results　and　the　characteristics　of　section　structures,　numerical　calculation　was　conducted.　The　test　and　simulation　results　show　that　for　special-shaped　bifurcated　CFT　short　column,　the　failure　mostly　appears　at　the　root　part　of　the　upper　column　branches　on　the　bifurcated　cross　section.　The　main　failure　exhibits　the　tear　of　the　steel　plate　far　from　the　neutral　axis　and　the　tear　of　whole　steel　plate　caused　by　the　crack　of　local　welding　seam.　The　bearing　capacity　of　the　enhanced　structure　of　encasing　circular　steel　tube　increases　by　7.　6%,　while　the　deformability　increases　by　14.　4　%,　and　best　energy　dissipation　ability　shows.　The　bearing　capacity　of　the　enhanced　structure　of　increasing　thickness　of　local　steel　tube　increases　by　9.　2　%,　but　the　deformability　decreases　by　18.　7　%　.　The　bearing　capacity　of　the　enhanced　structure　of　increasing　thickness　of　all　steel　tube　little　increases,　while　the　deformability　significantly　decreases.　The　proposed　simplified　finite　element　model　for　special-shaped　bifurcated　CFT　short　column　with　multiple　cavities　exhibits　well　efficiency.　And　the　accuracy　can　satisfy　the　demand　of　engineering　design.　©　2024　Chinese　Vibration　Engineering　Society.　All　rights　reserved.