This　paper　researches　the　dynamic　response　characteristic　of　the　cycloid　bevel　gear　under　a　wide　range　of　operation　speed　and　torque,　and　proposes　a　new　method　of　semi-analytical　FEM.　The　new　method　can　precisely　present　the　key　factors　of　the　gear　tooth　such　as　the　tooth　geometry　and　tooth　contact　stress,　which　influences　the　dynamic　characteristic　of　the　cycloid　bevel　gear　significantly.　Different　from　the　conventional　method,　the　non-line　factors　such　as　the　static　transmission　error,　time-varied　stiffness　and　meshing　frequency　variation　are　no　longer　considered　as　the　excitation.　However,　every　time　step　of　gear　meshing　is　considered　to　calculate　the　dynamic　contact　stress　and　dynamic　transmission　error,　and　finally　present　the　non-line　vibration　characteristic　of　cycloid　bevel　gear.