Motion state of meshing pairs of swing movable tooth during one motion cycle is studied and meshing process is analyzed.The formula of relative angular velocity is deduced.Variation curve of relative angular velocity is plotted and variation rule is analyzed.Specific sliding formula of conjugate profile is deduced to analyze profile abrasion of swing movable tooth conjugate profile.Variation curve of specific sliding is plotted and variation rule is analyzed according to a calculating example.The above research provided theoretical basis for profile abrasion

transmission efficiency and elastohydrodynamic lubrication of swing movable tooth transmission.