Abstract:The lubricating oil is known as the "blood" of mechanical equipment，it can lubricate, clean, cool, seal, reduce wear,prevent rust and corrosion of mechanical equipment, provide guarantee for normal and stable operation of mechanical equipment. This paper analyses the source of oil pollution in the process of equipment operation, hazards and other factors. Comparing the purification technology of high clean lubricating oil in domestic and abroad, combined with the data analysis of oil filtration based on practical data,providing important theoretical basis for actual production.