A　novel　welded-bolted　beam-to-column　joint,　connecting　double　channel　beams　to　concrete-filled　steel　tubular　(CFST)　columns,　is　proposed　for　a　prefabricated　steel　structure　that　only　need　bolted　assembly　on　site　in　construction.　To　investigate　the　seismic　performance　of　the　proposed　joint,　eight　full-scale　specimens　were　designed　and　tested　under　cyclic　loads,　and　the　joint　moment　resistance,　stiffness,　hysteretic　behaviors,　slipping　behaviors,　ductility,　and　and　energy　dissipation　capacity　were　analyzed.　Finite　element　models　were　built　and　validated　by　the　test　results,　and　the　bolt　tensions,　the　friction　between　slip　surfaces　and　the　bearing　force　on　the　bolt　hole　were　further　investigated　by　the　finite　element　analysis.　According　to　the　results,　the　slip　load　of　the　bolted　channel　becomes　larger　and　the　hysteretic　curve　becomes　plumper　with　the　increase　of　the　number　or　the　diameter　of　the　bolts.　The　increased　bolt　hole　size　showed　no　significant　effect　on　the　plumpness　of　the　hysteretic　curve　but　would　increase　the　slip　distance,　thus　increasing　the　energy　dissipation　capacity.　Compared　with　the　welded　joints　from　the　FEA　results,　the　welded-bolted　joints　could　develop　larger　rotation　capacity,　energy　dissipation　capacity　and　ultimate　moment.　Based　on　the　investigations,　the　proposed　novel　joints　could　be　designed　as　rigid　joints.　Based　on　the　investigation,　formulas　of　the　yield　and　ultimate　moment　resistance　of　the　welded-bolted　joints　were　proposed　and　validated　by　the　experimental　results.