The oil sludge separator is an early, mature, and versatile method for treating oil-containing sludge. It has evolved from vacuum filtration to pressure filtration, to roller pressing filtration, and finally to centrifugal dewatering, achieving separation of oil-containing sludge from solid-liquid phases to oil, water, and solid phases. The separated water phase is then processed at a wastewater treatment plant, the oil phase is returned to the refinery for reprocessing, and the filter cake is typically disposed of through landfilling, incineration, biological treatment, and some comprehensive utilization measures.