The utility model relates to the field of cooling of oil-immersed self-cooled transformers, in particular to a movable spray cooling device for an oil-immersed self-cooled transformer, which is convenient to store and install. The connecting base comprises a connecting part, two locking parts, a connecting table and a connector, the connecting table is arranged on the upper portion of the connector, mounting holes are formed in the two sides of the connecting table, and the two locking parts are mounted on the two sides of the connecting table through locking screws respectively. The connecting part comprises a first outer bulge, a first inner bulge, a second inner bulge, a second outer bulge and a hose; a first outer protrusion, a first inner protrusion, a second inner protrusion and a second outer protrusion are arranged on the two sides of the hose respectively, a first groove is formed between the first outer protrusion and the first inner protrusion, a second groove is formed between the second inner protrusion and the second outer protrusion, locking parts are arranged in the first groove and the second groove respectively, each locking part comprises a clamping ring and a locking screw, and the clamping rings are placed in the grooves. According to the utility model, the working temperature of the transformer can be quickly reduced, and the long-term stable work of the transformer is ensured.