Through many years hard effort, it developed with success the ZLY serial engine oil purification and discolourization purifier which is a breakthrough in oil decolourization a world wide difficulty. This purifier can remove the tiny impurity dispersed in oil such as carbon particles and deep oxides, as well as bad substance such as colloid and bitumen. Thus, the clarity of oil is recovered, engine oil quality improved, performance of engine restored, abrasion reduced, these would ensure correct operation of lubricant system of a engine and extend the life time of engine oil and engine as well. This kind of purifier is applicable to purification of various engine oil used transport facilities such as ship and automobile.