Prefabrication　assembly　technology　has　been　widely　recognized　due　to　its　rapid　construction,　minimal　environmental　impact,　and　superior　quality　of　precast　components.　The　reliability　and　construction　convenience　of　the　connection　joints　of　precast　components　are　particularly　important.　In　this　paper,　a　novel　Ultra　HighPerformance　Concrete　(UHPC)-filled　concrete-filled　steel　tube　(CFST)　socket　connection　(UCSC)　was　proposed　for　the　column-beam　connection.　To　explore　the　shear　behavior　and　shear　load　transfer　mechanism　of　UCSC　joints,　four　direct　shear　experiments　were　conducted　in　terms　of　different　parameters　(socket　depth,　presence　of　studs).　Meanwhile,　ABAQUS　was　used　to　perform　a　systematic　parametric　analysis　(socket　length,　embedded　length,　outer　diameter　of　CFST,　thickness　of　steel　tube).　The　results　indicated　that　the　shear　performance　of　UCSC　joints　was　significantly　influenced　by　both　the　socket　depth　and　the　outer　diameter　of　CFST.　The　proposed　finite　element　model　(FEM)　can　predict　the　load-displacement　relationships　of　UCSC　joints　with　a　maximum　peak　load　error　of　2.3　%.　Combining　the　experimental　results　and　numerical　results,　a　simplified　calculation　model　was　formulated　to　accurately　estimate　the　shear　bearing　capacity　of　UCSC　joints,　and　was　verified　by　numerical　and　experimental　results　with　a　maximum　error　of　8.6　%.　The　research　results　have　practical　implications　for　the　preliminary　design　of　UCSC　joints　to　avoid　non-ideal　failure　mode.