The　prefabricated　assembly　structure　adopts　a　new　joint　structure　and　construction　method,　which　has　the　advantages　of　low　environmental　pollution,　high　construction　quality,　and　less　traffic　interference.　At　present,　prefabricated　structures　have　been　widely　used　in　the　field　of　building　construction　and　bridge　engineering,　but　less　in　the　application　of　underground　comprehensive　pipe　gallery.　In　view　of　this,　this　paper　proposed　a　new　type　of　assembled　composite　shell　system　underground　comprehensive　pipe　gallery　structure.　The　formwork　is　made　of　high-performance　materials,　and　connectors　are　set　between　the　formwork,　and　the　load-bearing　reinforcement　of　the　composite　shell　pipe　gallery　component　was　set　outside　the　formwork.　Quasi　static　tests　were　carried　out　on　6　specimens　of　composite　shell　pipe　gallery　T-joints　to　study　the　mechanical　properties　of　the　joints　and　the　integrity　of　the　connection　interface.　The　results　show　that　the　bearing　capacity,　stiffness　and　ductility　of　composite　shell　T-joints　are　basically　equivalent　to　those　of　cast-in-place　(CIP)　reinforced　concrete　shear　walls,　which　verifies　the　good　seismic　performance　of　fabricated　joints.　When　the　specimen　is　in　the　yield　and　bearing　capacity　state,　the　joint　surface　between　the　formwork　and　the　post　cast　concrete　is　good,　which　can　effectively　ensure　that　the　formwork　and　the　concrete　maintain　the　common　force.　The　bearing　capacity　of　upper　and　lower　T-joints　of　composite　shell　with　shear　reinforcement　is　10∼15%　higher　than　that　of　CIP　structure.　In　addition,　a　calculation　formula　for　the　bearing　capacity　of　the　T-shaped　joint　of　the　composite　shell　was　proposed　and　its　accuracy　was　verified　through　test　results.　This　study　can　provide　technical　support　for　seismic　design　of　prefabricated　underground　pipe　gallery.　©　2023　Institution　of　Structural　Engineers