The invention belongs to the field of filtration of insulating oils and particularly discloses a vacuum filtering device for natural ester insulating oil, comprising a main oil tank, a pre-filter, a coalescence filter, a fine filter, an adsorbing filter, a vacuum separator and a vacuum system; the devices are communicated through pipelines. The vacuum filtering device for natural ester insulating oil can meet the requirements for filtration of natural ester insulating oils produced by refining processes, can also meet the requirements of contaminated natural ester insulating oil for filtration, purification, performance improvement and the like, and is small in floor area, good in safety and reliability, low in operation cost and easy to industrially popularize.