Concrete-filled　double　steel　tubular　(CFDST)　columns　have　been　proposed　in　recent　years.　This　paper　presents　the　performance　analysis　and　a　new　bearing　capacity　calculation　method　of　circular　CFDST　stub　columns　under　axial　compression.　In　order　to　establish　accurate　finite　element　(FE)　model,　various　constitutive　models　for　both　the　concrete　infill　and　steel　tubes　are　analyzed　and　compared　with　experimental　results　in　FE　analysis,　and　the　suitable　constitutive　models　for　sandwich　concrete,　core　concrete　and　steel　tube　are　proposed　in　the　FE　model　developed.　Based　on　the　validated　numerical　model,　the　variation　of　confining　stress　between　steel　tube　and　concrete　is　analyzed　in　detail.　In　addition,　parametric　studies　are　conducted　to　investigate　the　effects　of　concrete　strength,　external　tube　thickness,　inner　tube　thickness,　diameter　ratio　of　inner　tube　to　external　tube　and　yield　strength　of　steel　tube　on　the　axial　compressive　performance　of　circular　CFDST　stub　columns.　A　new　simplified　formula　based　on　the　confining　pressure　is　proposed　to　evaluate　the　ultimate　bearing　capacity　of　the　circular　CFDST　stub　columns.　Based　on　the　comparisons　with　experimental　results　and　numerical　simulation　results,　it　is　shown　that　the　proposed　formulae　for　the　circular　CFDST　stub　columns　appear　to　be　satisfactory.