This　study　investigates　the　axial　compression　performance　of　ultra-high　performance　concrete　(UHPC)-filled　double　skin　steel　stub　columns　with　outer　stainless　steel　tube　(UFDSST).　Fifteen　UFDSST　stub　columns　and　three　UHPC　filled　duplex　stainless　steel　tube　(UFSST)　stub　columns　were　tested　under　axial　compression.　The　test　parameters　include　the　section　hollow　ratio　(chi),　the　diameters　to　thickness　ratio　of　inner　carbon　steel　tube　(Di/ti)　and　outer　stainless　steel　tube　(Do/to).　The　test　results　show　that　it　is　feasible　to　utilize　UFDSST　stub　columns　instead　of　UFSST　stub　columns　to　mitigate　the　impact　of　UHPC＇s　brittle　failure　under　compression　on　the　members.　UFDSST　columns　exhibit　80　%-101　%　load-bearing　capacities　to　UFSST　stub　columns　while　with　reduced　self-weight.　Furthermore,　the　ductility　index　(I10)　of　UFDSST　stub　columns　has　increased　by　8.8　%-21.4　%　compared　to　UFSST　stub　columns,　and　the　toughness　index　(T.I.)　has　increased　by　12.7　%-21.0　%.　A　finite　element　model　(FEM)　capable　of　more　accurately　simulating　the　axial　compression　mechanical　behavior　of　UFSST　and　UFDSST　stub　columns　was　developed.　The　mechanism　analysis　using　the　FEM　showed　that　decreasing　Do/to　can　facilitate　the　earlier　activation　of　the　constraining　effect　of　the　outer　stainless　steel　tube,　and　the　constraint　effect　of　the　inner　steel　tube　emerged　after　the　peak　load,　primarily　contributing　to　the　ductility　performance.　The　test　results　were　used　to　evaluate　the　feasibility　of　existing　calculation　models　in　codes　and　literature　for　designing　UFDSST　stub　columns.　A　modified　computational　model　considering　the　constraint　effect　of　stainless　steel　tubes　on　UHPC　and　the　strain-hardening　material　characteristics　was　proposed.