The product is equipped three-stage purifictaion, easy to operate, very low price, no need of purification paper, no contamination to the ground. The product can effectively purify the tiny and fine mechanical impurity min oil. Enabling it to be a prior choiceof power industry petroleum, chemical, metallurgy, mechanics, and railway for oil filling. Oil drawing, and high precision impurity removal of mutual inductor., lathe, and oil breaker which do not use large quantity of oil.