Considering　the　distinct　fatigue　failure　patterns　exhibited　by　concrete-filled　steel　tubular　(CFST)　K-joints,　this　study　introduces　a　novel　design　featuring　internally　positioned　studs　arranged　in　a　circular　configuration　along　the　intersecting　weld　seam,　referred　to　as　the　CFST　KSC-joint.　A　comprehensive　full-scale　fatigue　test　was　conducted　on　the　CFST　KSC-joint　model,　with　its　hot-spot　stress　distribution　and　fatigue　failure　mechanisms　compared　to　those　of　CFST　K-joints　without　studs　(CFST-K)　and　with　array-arranged　studs　(CFST-KSA).　Further,　finite　element　parameter　analysis　was　employed　to　explore　the　influence　of　the　circular　arrangement　and　geometric　parameters　of　the　internal　studs　on　hot-spot　stress.　Drawing　upon　the　existing　array-arranged　stud　configurations,　an　optimized　circular　arrangement　of　internal　studs　for　CFST　K-joints　was　proposed.　Our　findings　reveal　that　the　failure　modes　of　CFST　KSC-joints　mirror　those　of　CFST-K　and　CFST　KSA-joints,　involving　stages　of　fatigue　crack　initiation,　propagation,　and　ultimate　failure.　The　circular　arrangement　of　internal　studs　outperforms　the　array　arrangement　in　reducing　hot-spot　stress　and　improving　fatigue　life,　thereby　enhancing　the　fatigue　performance　of　the　joint.　Among　the　stud　size　parameters,　an　increase　in　stud　diameter　(phi)　significantly　improves　the　effectiveness　of　reducing　hot-spot　stress,　whereas　variations　in　stud　length　(h)　have　a　minimal　impact.　The　optimal　arrangement　of　internal　studs　near　the　intersecting　weld　involves　placing　a　single　ring　of　studs　along　the　length　of　the　intersecting　weld　at　positions　0　degrees,　22.5　degrees,　45　degrees,　90　degrees,　135　degrees,　and　180　degrees.