A　wet　connection　for　prefabricated　slabs　using　Ultra-High-Performance　Concrete　(UHPC)　was　proposed　and　experimentally　investigated.　Influence　of　parameters　such　as　the　lap　length　of　dowel　rebar,　the　groove　key　size　and　the　arrangement　of　post-placed　rebar　in　grooves　were　comparatively　explored.　Four　tensile　specimens　and　eight　flexural　specimens　were　designed　and　tested.　The　crack　development,　failure　mode,　load-deformation　characteristics,　strains　and　bearing　capacity　were　observed　and　analyzed.　The　results　indicated　that　the　lap　length　of　dowel　rebar　significantly　influenced　the　failure　mode.　Dowel　rebar　with　insufficient　lap　length　in　postcast　UHPC　connection　exhibited　rebar　pulling-out　failure,　and　lap　length　of　12　times　diameter　of　the　dowel　rebar　could　achieve　mechanical　performance　equivalent　to　cast-in-situ　construction.　Based　on　analysis　of　the　test　results,　the　prediction　for　tensile　capacity　of　UHPC　connection　was　recommended　based　on　existing　prediction　formula　for　bonding　stress　of　rebar　in　concrete,　and　the　theoretical　predicting　formulas　for　flexural　bearing　capacity　and　deflection　of　prefabricated　slabs　having　different　dowel　rebar　lap　lengths　in　UHPC　connection　were　proposed,　which　showed　good　agreement　with　test　results.