Concrete　-filled　steel　tubes　are　widely　applied　in　offshore　structures,　which　often　being　exposed　to　aggressive　ocean　climate.　This　has　recently　led　to　the　introduction　of　concrete　-filled　aluminum　alloy　tubular　(CFAT)　columns,　of　which　aluminum　alloy　tube　is　used　as　a　superior　anti　-corrosion　metal　material.　However,　limited　research　has　led　to　the　design　of　CFAT　columns　not　being　included　in　the　current　design　specifications,　limiting　their　engineering　applications.　Accordingly,　in　this　paper,　an　experimental　program　including　9　CFAT　specimens　was　launched　to　further　investigate　the　compressive　behavior　of　CFAT　short　columns　and　to　clarify　the　confinement　mechanism　in　such　columns.　The　test　results　indicate　that　the　ultimate　capacity　of　CFAT　short　columns　is　improved　with　the　increase　of　concrete　strength　or　the　decrease　of　tube　diameter　-towall　thickness　ratio.　Based　on　the　experimental　results,　the　finite　element　model　(FEM)　was　established,　and　then　used　to　clarify　the　confinement　mechanism　of　CFAT　columns　and　investigate　the　effects　of　the　salient　parameters　on　the　behavior　of　such　columns.　By　comparing　with　the　existing　experimental　results,　the　accuracy　of　current　strength　calculation　formulas　for　CFAT　columns　was　assessed,　and　the　conclusion　indicates　that　there　is　an　unexpected　deviation　in　the　prediction　results.　To　this　end,　a　simplified　strength　prediction　formula　for　CFAT　columns　was　proposed,　which　successfully　introduced　a　novel　confinement　factor　that　well　reflects　the　confinement　effect　of　the　concrete　core.　This　confinement　factor　considers　the　effects　of　proof　stress,　concrete　strength,　and　tube　diameter　-to　-wall　thickness　ratio.　Finally,　compared　with　other　formulas,　the　proposed　formula　has　better　performance　in　predicting　results.