The utility model provides an automatic flushing device for a transformer cooling system, and belongs to the field of cleaning devices for transformer cooling systems. The automatic flushing device comprises a transformer, wherein a cooling system is arranged on the transformer; a horizontal fixed pole, a vertical movable pole, bent plates, a motor II, a motor I, a chain I, a chain, a gear, a cross-shaped buckling plate, an air blast spray head, a horizontal pressure plate, a vertical rod moving rail, a fastening screw, a travel switch, a thimble and a control box are arranged; the horizontal fixed pole is fixed to the cooling system of the transformer through two bent plates; the motor I and the gear are fixed to the two ends of the horizontal fixed pole respectively; the cross-shaped buckling plate is arranged on the horizontal fixed pole between the motor I and the gear; a horizontal guide rail is arranged on the larger surface of the cross-shaped buckling plate. The cleaning efficiency is high, manpower is not needed, and the labor force is saved greatly.