Through-tenon　joints　are　widely　used　in　ancient　timber　buildings.　To　study　the　influence　of　the　gaps　between　mortise　and　tenon　shoulder　on　the　seismic　performance　of　through-tenon　joints,　a　1:3.52　scaled　model　was　constructed　and　used　for　low　cyclic　loading　test.　Finite　element　analysis　was　conducted　to　study　the　mechanical　behavior　of　the　through-tenon　joint.　The　seismic　performance　parameters　of　the　model　such　as　moment　-rotation　hysteresis　curves,　envelope　curves,　degradation　of　rigidity,　and　energy　dissipation　capacity　were　compared.　The　analyses　showed　similar　changing　characteristics,　which　indicated　that　the　finite　element　analysis　results　were　reliable.　Based　on　the　results,　7　through-tenon　joint　finite　element　analysis　models　with　different　gaps　between　mortise　and　tenon　shoulder　were　established.　The　seismic　performance　of　each　of　the　through-tenon　joints　with　different　gaps　between　mortise　and　tenon　shoulder　were　studied.　The　moment-rotation　hysteresis　curve　of　the　through-tenon　joint　had　an　obvious　pinching　effect,　and　the　through-tenon　joint　had　good　rotational　loading　capacity　and　good　deformation　ability.　The　peak　rotational　loading　capacity,　initial　stiffness,　and　energy　dissipation　capacity　of　the　joint　decreased,　while　the　gap　between　mortise　and　tenon　shoulder　increased.