The invention relates to a solvent recovery technique of a coke chemical industry, in particular to a coke oven gas debenzolization system. The coke oven gas debenzolization system comprises a benzene washing tower, a first pipeline for being connected with the benzene washing tower, a gas pumping device, a debenzolization tower, a condensation cooling unit, a light benzene oil-water separator and a crude benzene collecting device. The gas pumping device is arranged on the first pipeline, the debenzolization tower is connected with the condensation cooling unit, the condensation cooling unit is simultaneously connected with the light benzene oil-water separator and one part of the first pipeline far away from the benzene washing tower, the light benzene oil-water separator is further connected with the crude benzene collecting device, and the debenzolization tower, the condensation cooling unit and the part of the first pipeline far away from the benzene washing tower are located in a same pressure system. The coke oven gas debenzolization system can use the gas pumping device to pump out gas in the same pressure system where the debenzolization tower, the condensation cooling unit and the part of the first pipeline far away from the benzene washing tower are located, and further reduces pressure in a system where the debenzolization tower, so that benzene family hydrocarbon content in lean oil is reduced.