The geometrical parameters of the involute arc cylindrical gear are introduced.Starting from their tooth flank equations
the equations of the lines of contact and contact ratio are analyzed.On this basis
it proposes the method for calculating the contact stress and the tooth root stress of the involute arc cylindrical gears is proposed and the stress of spur gear and the involute arc cylindrical gears by the FE method is analyzed.The tooth surface contact stress and the tooth root stress of arc cylindrical gear is superior to spur cylindrical gear.