Socket　connections　have　been　widely　used　as　one　of　the　most　effective　connection　methods　for　precast　columns　and　adjacent　members.　To　expand　the　application　of　socket　connections,　a　novel　concrete-encased　concrete-filled　steel　tube　(CFST)　column-cap　beam　socket　joints　with　Ultra　High-Performance　Concrete　(UHPC)　grouting　is　proposed　in　this　study.　Quasi-static　tests　are　performed　on　concrete-encased　CFST　column-cap　beam　socket　joints　with　various　socket　depths　to　investigate　their　seismic　performance　and　reliability.　Numerical　models　are　also　established　and　verified　based　on　experimental　results　to　further　extend　the　research　specimens.　Additionally,　a　calculation　model　for　the　socket　joints　is　developed.　The　research　results　indicate　that　the　proposed　socket　joint　exhibits　excellent　seismic　performance,　which　is　established　through　analyses　of　its　lateral　load　capacity,　energy　dissipation　capacity,　stiffness　degradation,　and　failure　modes.　Furthermore,　numerical　models　are　effectively　employed　to　simulate　the　hysteretic　behavior　and　damage　progression　of　the　socket　column-cap　beam　joints　with　a　high　degree　of　accuracy.　When　comparing　the　developed　calculation　model　with　experimental　and　numerical　results,　it　becomes　evident　that　the　model　can　reliably　predict　the　joint＇s　lateral　load　capacity,　making　it　suitable　for　the　preliminary　seismic　design　of　these　innovative　socket　joints.