The invention relates to a vacuum impregnation processing system of transformers. The system comprises a processing tank body, a pair of upper and lower impregnation tank bodies and a pair of upper and lower conveyor belts; the upper and lower impregnation tank bodies are arranged in the processing tank body and both provided with heating mechanisms; the upper and lower conveyor belts are arrangedon the two impregnation tank bodies respectively, the sections, located on the upper portions of the upper and lower impregnation tank bodies, of the upper and lower conveyor belts are immersed in impregnation solutions in the upper and lower impregnation tank bodies respectively, and a transition conveyor belt is arranged between the upper conveyor belt and the lower conveyor belt; the processing tank body is externally and symmetrically provided with a waste liquid tank and a liquid supply tank which are both communicated with the impregnation tank bodies through pipelines. The vacuum impregnation processing system of the transformers has the advantages that the manual labor can be reduced, continuous production is achieved, and the impregnation effect and quality can be improved.