The　compressive　behavior　of　special-shaped　concrete　filled　tube　(CFT)　mega　column　coupled　with　multiple　cavities　is　studied　by　testing　six　columns　subjected　to　cyclically　uniaxial　compressive　load.　The　six　columns　include　three　pentagonal　specimens　and　three　hexagonal　specimens.　The　influence　of　cavity　construction,　arrangement　of　reinforcement,　concrete　strength　on　failure　feature,　bearing　capacity,　stiffness,　and　residual　deformation　is　examined.　Experimental　results　show　that　cavity　construction　and　reinforcements　make　it　possible　to　form　a　combined　confinement　effect　to　in-filled　concrete,　and　the　two　groups　of　special-shaped　CFT　columns　show　good　elastic-plastic　compressive　behavior.　As　there　is　no　axial　bearing　capacity　calculation　method　currently　available　in　any　Code　of　practice　for　special-shaped　CFT　columns,　values　predicted　by　normal　CFT　column　formulas　in　GB50936,　CECS254,　ACI-318,　EC4,　AISCI-LRFD,　CECS159,　and　AIJ　are　compared　with　tested　values.　The　calculated　values　are　lower　than　the　tested　values　for　most　columns,　thus　the　predicted　bearing　capacity　is　safe.　A　reasonable　calculation　method　by　dividing　concrete　into　active　and　inactive　confined　regions　is　proposed.　And　high　accuracy　shows　in　estimating　special-shaped　CFT　columns　either　coupled　with　multiple　cavities　or　not.　In　addition,　a　finite　element　method　(FEM)　analysis　is　conducted　and　the　simulated　results　match　the　test　well.