Study on theory of generation processing arc cylinder-gears, machining cutter was designed by the blade fillet and the top tooth edge generating the tooth root fillet of arc cylinder-gears, to build the linear tooth-surface equation of cutter-gear and the position vector of blade fillet curvature center. The linear tooth surface equations and fillet tooth surface equation were derived based on coordinate transformation principle, meshing equation, meshing geometry principle and kinetic theory. The precise 3D model was established. It verifies the feasibility of generation processing the arc cylinder-gears and achieves smooth transition both working and fillet tooth surface of arc cylinder. It provides theoretical basis for tooth contact analysis, tooth bending stress and kinetic analysis, further offers accurate data to numerical control machining and systematically guides the experimental research and practical application.