Three　frame　joints　strengthened　by　self-compacting　concrete　and　one　unstrengthened　joint　were　produced　for　comparison.　Static　tests　using　MTS　servo　loading　system　on　the　frame　joints　under　secondary　load　were　carried　out　to　study　the　influence　of　different　initial　forces　on　the　seismic　performance.　The　initial　column　axial　load　ratio　was　0.3,　and　the　initial　forces　of　the　beam　were　0,　0.25　and　0.50　times　the　estimated　cracking　load　of　the　unstrengthened　specimen　beam　end.　The　results　of　the　damage　process,　strain　of　the　old　steel　and　new　steel,　the　load-displacement　hysteretic　loops　were　analyzed.　It　is　found　that　the　interactive　performance　of　the　old　concrete　and　new　concrete　is　good　when　using　self-compacting　concrete　to　strengthen　the　frame　joints.　Considering　the　impact　of　the　initial　load　of　the　beam　end,　the　ultimate　strength,　displacement,　and　beam　end　displacement　ductility　coefficient　of　the　reinforced　joints　etc.　are　reduced.　The　degree　of　reduction　increases　with　the　initial　load,　which　should　be　considered　in　the　design　of　strengthening.