Circular arc tooth line cylindrical gear is a kind of cylindrical gear with convex and concave curve teeth which is processed by spiral bevel gear milling machine. The tooth line of this kind of gear is circular arc, and has the characteristics of symmetry about the central section of tooth width. The mathematical model of circular arc tooth profile circular arc tooth line cylindrical gear is established according to spiral bevel gear milling principle, and the 3 D solid model of double-arc tooth profile gear and quadruple-arc tooth profile gear is established according to the gear mathematical model. Finally, the contact stress analysis of the gear is carried out by using the finite element analysis software, and the static contact stress are obtained, the contact stress of quadruple-arc tooth profile gear is about 80% of the double-arc tooth profile gear. The research results can provide a theoretical basis for the design and application of circular arc tooth profile circular arc tooth line cylindrical gear.