This　paper　introduces　a　new　large　step-tapered　hollow　(STH)　pile　used　in　a　karst　area　and　its　construction　method.　To　reveal　the　advantages　of　this　pile　type,　a　15　m　dia.　STH　pile　in　Ji＇an　Shenzhen　Bridge　was　simulated　using　Flac3D　software.　The　vertical　bearing　capacity　was　assessed　by　considering　the　influences　of　the　width　and　number　of　the　variable　cross-sections　and　the　soil　characteristics　around　the　pile.　In　addition,　new　large　STH　piles　of　two　different　forms　were　assessed　to　expand　the　practical　application　of　such　piles.　The　results　showed　that,　for　a　large-diameter　pile,　the　concrete　utilisation　rate　and　the　vertical　bearing　capacity　of　the　pile　were　improved　by　the　design　of　hollow　and　variable　cross-sections.　The　optimal　range　of　the　taper　angle　for　the　large　STH　pile　was　found　to　be　2.68-5.36°　and　the　optimal　number　of　variable　cross-sections　was　found　to　be　between　two　and　four.　The　bearing　capacity　increased　with　an　increase　in　the　soil　shear　strength　parameters　and　the　pile　was　deemed　suitable　for　stiff　strata.　The　results　of　this　work　could　facilitate　design　practice　for　large　STH　piles.　©　2020　ICE　Publishing.　All　rights　reserved.