Series ZY single-stage-vacuum insulating oil purifier, which is mainly applied in the power station, industrial and mining enterprises to purify the different of unqualified insulating oils, like the transformer oil, mutual inductor oil, switch oil and so on. Series ZY can remove water; trace water, gas, particles from oil quickly and effectively, improving and recovering oil's dielectric strength. Also, this ZY oil purifier can be used as vacuum drying, and vacuum oiling for electric-equipments.