A　novel　UHPC-shell　strengthened　prefabricated　concrete　bent　cap　(USPCBC)　was　proposed　in　this　study.　The　prefabricated　UHPC-shell　acts　as　permanent　formwork.　A　RC　bent　cap　(RBC)　and　three　USPCBCs　with　different　types　of　interface　and　different　thicknesses　of　UHPC-shell　were　tested.　Results　show　that　USPCBCs　exhibited　high　load　capacity　and　good　deformability.　The　cracking　load　and　ultimate　load　of　USPCBC　were　42.1%　and　13.8%　higher　than　that　of　RBC,　respectively.　However,　the　interface　separation,　outward　dilation　of　core　concrete　and　vertical　cracking　of　UHPC　shell　were　observed.　The　achieved　results　showed　that　the　damages　in　USPCBC　concen-trated　on　the　interface　of　the　UHPC　and　the　normal　concrete.　With　the　use　of　shear　key　between　UHPC　shell　and　inner　concrete,　the　cracking　load　of　interface　and　ultimate　load　of　USPCBC　were　increased　by　50%　and　12.1%.　For　USPCBCs,　a　finite　element　simulation　has　been　developed.　The　commercial　FE　program　ABAQUS　was　used.　The　optimization　of　the　strength　of　UHPC　and　inner　normal　concrete　were　proposed　for　USPCBCs.　Finally,　the　theoretical　formula　considering　the　interaction　of　UHPC　shell　and　core　concrete　to　evaluate　the　load　capacity　was　proposed.　The　formula　was　verified　to　be　a　good　calculation　accuracy.