In　order　to　investigate　meshing　force　of　the　swing　movable　tooth　transmission　actuated　by　cam,　academic　and　work　tooth　profile　equations　of　the　central　inner　gear　are　deduced　based　on　its　transmission　principle.　According　to　the　suppose　of　stretch　small　distortion　and　distortion　congruity,　the　model　and　algorithm　of　meshing　force　analysis　under　theoretic　meaning　are　proposed,　the　presented　method　is　illuminated　through　an　example　of　meshing　force　calculation,　and　the　distributing　tendency　of　meshing　force　of　this　type　of　transmission　device　is　assumably　acquired.