This　paper　investigates　the　axial　compressive　behavior　of　an　innovative　composite　wall　consisting　of　stainlessclad　bimetallic　steel　faceplates　and　ultra-high　performance　concrete　(UHPC)　infill.　The　innovative　wall　can　address　three　major　challenges　of　traditional　steel-concrete　composite　walls,　i.e.,　rapid　degradation　of　the　lateral　stiffness,　insufficient　ductility　of　the　concrete　infill,　and　limited　corrosion　resistance　of　steel　faceplates.　A　total　of　12　tests　were　first　conducted,　considering　the　effects　of　normalized　faceplate　slenderness　ratio　(7),　concrete　type,　and　steel　type.　Finite　element　models　were　then　developed　and　benchmarked　for　parametric　studies.　Results　from　tests　and　parametric　analysis　showed　that:　(1)　failure　modes　of　the　composite　wall　were　local　buckling　of　steel　faceplate　and　concrete　crushing;　(2)　increasing　7　significantly　reduced　the　axial　compressive　strength　of　the　composite　wall　and　critical　buckling　stress　of　the　steel　faceplate,　but　had　a　negligible　effect　on　the　axial　stiffness;　(3)　UHPC　greatly　improved　the　compressive　strength　and　axial　stiffness　of　the　composite　wall,　but　also　resulted　in　a　more　brittle　behavior.　Finally,　the　applicability　of　current　design　provisions　(i.e.,　CECS:546-2018,　Eurocode　4,　and　AISC　360-22)　for　estimating　the　axial　compressive　strength　was　evaluated,　and　a　new　design　equation　was　proposed.