The invention relates to the technical field of valve maintenance, and particularly discloses an automatic opening and closing tool for a valve. The automatic opening and closing tool for the valve comprises a yoke fixing module, a base module and a torque generator, wherein the torque generator is connected with the base module through a transmission mechanism, torque of the torque generator is transmitted to the base module, so that the base module rotates along a central axis, and the yoke fixing module is composed of a plurality of connecting rods and forms a supporting structure with an adjustable angle and is used for supporting and fixing the base module and the torque generator. According to the tool, an adjustable valve hand wheel clamping mechanism is adopted, valve hand wheels with different diameters can be suitable for; the connecting rods in the yoke fixing module adopts tooth-shaped positioning structures and can be applied to valves with hand wheels in different directions, and in the situation that radiation dose is high, valve specification is high, and operation personnel are not convenient to operate on site, a remote controller can be used for remotely operating the torque generator to act.