As　a　new　type　of　composite　girders,　composite　girders　with　corrugated　steel　webs　and　concrete-filled　steel　tubular　(CSW-CFST)　truss　chords　are　extensively　utilized　in　bridge　engineering.　To　examine　the　structural　behavior　of　composite　girders　with　CSW-CFST　truss　chords　subjected　to　combined　flexure　and　torsion,　model　tests　and　finite　element　analysis　(FEA)　are　employed.　Using　these　efficient　tools,　the　strain　distribution,　deformation　law,　failure　mode,　and　bearing　capacity　of　these　composite　girders　subjected　to　pure　torsion　and　combined　flexure　and　torsion　are　methodically　obtained.　The　primary　objectives　are　to　probe　the　applicability　of　existing　flexure-torsion　relation　curves　and　introduce　the　calculation　method　for　the　bearing　capacity　of　composite　girders　with　CSW-CFST　truss　chords　subjected　to　combined　flexure　and　torsion.　The　obtained　results　reveal　that　their　failure　mode　is　influenced　by　the　initial　torsional　moment.　Further,　their　bearing　capacities　due　to　the　applied　initial　torsional　and　bending　moments　can　be　maximally　enhanced　by　about　21.6%　and　6.6%,　respectively.　The　deviation　between　the　predicted　bearing　capacity　by　the　FEA　and　that　obtained　from　the　tests　is　less　than　8.6%,　demonstrating　the　high　accuracy　of　the　FEA　model.　The　contribution　of　the　torsional　moment　to　the　flexural　bearing　capacity　is　either　ignored　or　underestimated　by　the　existing　flexure-torsion　relation　curves,　with　a　minimum　deviation　of　about　22.3%.　By　comparing　the　results　acquired　by　the　extended　FEA　and　the　calculation　method　proposed　in　this　paper,　it　is　proved　that　the　proposed　calculation　method　for　the　bearing　capacity　of　composite　girders　with　CSW-CFST　truss　chords　subjected　to　combined　flexure　and　torsion　may　reduce　the　deviation　from　22.3%　to　8.3%.