Self-cleaning circulating filtration system

The utility model discloses a self-cleaning circulating filtration system, which is characterized in that workpiece sump oil received by an oil receiving basin enters a sump oil tank after passing through an intermediate filter, and an oil supply pump III connected with the sump oil tank introduces oil into a transition oil tank through an oil filter II and a centrifugal filter; an oil supply pumpIV connected with the transition oil tank enables oil to enter the clean oil tank through a super-strong magnetic filter, a metal filter and a precise cloth bag filter, and an oil supply pump II connected with the clean oil tank enables the oil to be injected into a workpiece through an oil filter I; by controlling opening and closing of the related gate valves, the oil supply pump I can pump oilfrom the oil purifying tank to enter the metal filter to be flushed, the oil supply pump IV can pump oil from the transition oil tank to enter the super-strong magnetic filter to be flushed, and theflushed oil is introduced i