A　total　of　16　concrete-filled　high-strength　steel　tube　specimens　were　designed　to　evaluate　the　effects　of　shear-to-span　ratio　and　concrete　strength　on　the　shear　behavior　of　concrete-filled　high-strength　steel　tube　specimens.　The　failure　mode　and　shear-displacement　curve　of　the　specimens　were　obtained　through　the　test,　and　the　effects　of　shear-to-span　ratio,　core　concrete　strength,　and　other　parameters　on　the　failure　mode,　shear-displacement　curve,　shear-shear　strain　curve,　shear　strength,　and　shear　stiffness　were　compared.　The　results　show　that　similar　to　conventional　concrete-filled　steel　tube　specimens,　the　shear-to-span　ratio　is　the　key　parameter　controlling　the　failure　mode　of　the　concrete-filled　high-strength　steel　tube　specimens.　When　the　shear-to-span　ratio　is　0.2　or　0.5,　shear　failure　occurs;　when　the　shear-to-span　ratio　is　0.8　or　1.0,　shear-flexural　failure　occurs.　By　implementing　ultra-high　performance　concrete　(UHPC),　the　deformation　capacity　of　the　concrete-filled　high-strength　steel　tube　specimens　(with　a　shear-to-span　ratio　of　1.0)　is　reduced　by　61.4%.　However,　shear　strength　and　stiffness　increase　by　38.9%　and　85.7%,　respectively.　Additionally,　local　buckling　of　the　steel　tubes　is　effectively　delayed,　and　the　damage　degree　of　the　specimens　is　reduced.　The　inclination　angle　of　the　main　diagonal　cracks　in　the　core　concrete　decreases　with　an　increase　in　the　shear-to-span　ratio　but　is　not　affected　by　the　concrete　strength.　The　average　value　of　tested　shear　strength/calculated　shear　strength　(Vexp/Vu)　is　0.97,　with　a　deviation　of　0.03,　showing　higher　accuracy　and　smaller　dispersion.　It　is　considered　that　the　formula　can　accurately　predict　the　shear　strength　of　concrete-filled　high-strength　steel　tubes.　©　2025　Science　Press.　All　rights　reserved.