Coal liquefied oil boiling bed hydrogenation technique

The invention discloses a boiling bed hydrogenation technique for improving the coal liquefied oil light oil yield; catalytic cracking oil slurry clarified oil is distilled to obtian a light fraction and a heavy fraction, the heavy fraction is countercurrent mixed with hydrogen for hydro-upgrading reaction, the upgraded heavy fraction and the light fraction are mixed, and enter, together with coal liquefied oil and cycled liquid production oil, into a boiling bed reactor for hydrogenation reaction; a reaction effluent is separated to obtain liquid production oil, part of the liquid production oil returns back to the boiling bed reactor, and the rest of the liquid production oil is fractionally distillated to obtain various products. After upgrading of oil slurry, the content of mononuclear aromatics and polyaromatic hydrocarbons is greatly increased, the upgraded oil slurry is used as a hydrogen donor for the coal liquefaction oil boiling bed hydrogenation process, by the synergy of the coal liquefied oil and the hydrogen donor, the coal liquefied oil conversion rate can be significantly improved, the yield of light oil can be increased, at the same time, catalytic cracking slurry oil being difficult to process can be well utilized, and the economic benefit is very good.