Dirty oil purification treatment process

The invention discloses a dirty oil purification treatment process comprising the following steps: 1) pretreating dirty oil of which the water content is higher than 10% by virtue of a dirty oil heating pretreatment unit; 2) simultaneously conveying the dirty oil pretreated in the step 1), a dirty oil demulsifier A and a dirty oil demulsifier B into a dirty oil automatic dosing mixing reaction unit, and fully mixing to obtain a mixture; and 3) enabling the mixture to enter a mechanical dehydration unit for oil-water-solid-slag separation to obtain qualified oil. The dirty oil demulsifier A isa mixed solution composed of dodecyl dimethyl benzyl ammonium chloride, polyoxyethylene octyl phenol ether-10 and water; the dirty oil demulsifier B is polyacrylamide, and the concentration of the polyacrylamide is 0.05%-1%. After the dirty oil is treated by the process, the water content of the dirty oil can be reduced from 90% to 5% or less; and the solid content can be reduced to 2% or less, sothat the effects of dehyd