Low-loss combined transformer

The utility model relates to the related technical field of transformers, in particular to a low-loss combined transformer which comprises a transformer body and a distribution box, transformer oil is arranged in the transformer body, a cooling box filled with water is arranged in the distribution box, and an oil outlet pipe and an oil filling pipe are sequentially arranged outside the transformer body from bottom to top. One end of the oil outlet pipe extends into the distribution box and is communicated with an oil pump, an output port of the oil pump is provided with a conveying pipe, the conveying pipe extends into the cooling box and is communicated with the oil injection pipe, a plurality of air inlets communicated with the outside are formed in the side wall of the distribution box, and fans are arranged at the air inlets. Transformer oil is pumped out through the oil pump and flows along the conveying pipe, the conveying pipe exchanges heat with liquid in the cooling box, the transformer oil is cooled