The current situation and development prospect of deep processing of washing oil at home and abroad in recent years were introduced, and a new technology for deep processing of washing oil was proposed based on the existing deep processing technology of washing oil. The continuous distillation technology was used to separate and purify the main components in the washing oil, such as naphthalene, α-methylnaphthalene, β-methylnaphthalene, acenaphthene, fluorine and so on. High number of trays and low product purity during deep processing of washing oil were improved and some problems such as coking and tower plugging in this process were solved by combining high efficiency flow-guided sieve tray and BH type high efficiency packing technology. Taking the deep processing project of 50 000 tons per year of washing oil as an example, the economic benefit was about 123.49 million RMB per year, and the payback period of the project was 7.2 months.