The invention belongs to the technical field of power equipment and particularly relates to a cleaning device special for a transformer. The cleaning device special for the transformer comprises an oil tank and a gas tank. The oil tank is connected with an oil pipe. The gas tank is connected with a gas pipe. The oil pipe and the gas pipe are connected with a mixing chamber. An upper baffle plate and a lower baffle plate are arranged in the mixing chamber. The portion, which is far away from the end, connected with the oil pipe and the gas pipe, of the mixing chamber, of the mixing chamber is connected with a nozzle through a hinge seat. The nozzle is spherical. Spray holes with the same size are formed in the nozzle. The cleaning device special for the transformer has the beneficial effects that the use amount of cleaning oil liquid can be reduced, and the cleaning effect is clean and thorough.