The utility model relates to the technical field of automatic doors, and in particular relates to an arc automatic door. The arc automatic door comprises a top plate, movable door leaves and fixed door leaves, wherein a protecting plate is arranged on upper edges which encircle the movable door leaves and the fixed door leaves; the movable door leaves are divided into a drive door leaf and a driven leaf which is driven by the drive door leaf to open and close; at least one group of rotation arms are also arranged on the movable door leaves; one end of each rotation arm is hinged with the center of the top plate; the other end of each rotation arm is connected to the upper edges of the movable door leaves; a drive device and a transmission mechanism are also arranged on the movable door leaves so as to provide transmission power to realize the opening and the closing of the movable door leaves. By the arc automatic door, hanger rails are replaced with the rotation arms, and the hanger rails are matched with a trapezoid belt to drive to realize the opening and closing of the movable door leaves, so that the great potential safety hazard caused by hanging door bodies of the original hanger rail is avoided, the noise of sliding between the hanger rails and hanger components is eliminated, and the service life of the arc automatic door is prolonged; and in addition, the arc automatic door can be matched with an access control system to realize entrance authorization identification to realize a safe control function of preventing following, and can be applied to safe management of exits and entrances of important departments.