The invention provides a process and a device for preparing an oil product by mixing oil slurry, recycle oil and coker gas oil. The process comprises the following steps: mixing oil slurry generated by a catalytic cracking process, recycle oil and coker gas oil generated by a delayed coking process to obtain mixed oil, and carrying out a two-stage extraction process on the mixed oil, wherein extracting agent dimethyl sulfoxide is adopted in the first-stage extraction, and first-stage extraction liquid and first-stage raffinate are obtained after extraction; performing steam stripping on the first-stage extraction liquid to obtain aromatic hydrocarbon-rich oil, and performing steam stripping on the first-stage raffinate to obtain first-stage raffinate oil, wherein the first-stage raffinate oil is subjected to second-stage extraction, extraction agent N, N-dimethylacetamide is adopted for second-stage extraction, and second-stage extraction liquid and second-stage raffinate are obtained after extraction; and performing steam stripping on the secondary extraction liquid to obtain olefin and aromatic hydrocarbon, and performing steam stripping on the secondary raffinate to obtain oil rich in saturated hydrocarbon. According to the method, three oil products are firstly mixed and extracted, an extraction phase is used for producing carbon materials such as asphalt blend oil and needle coke, and a raffinate phase is used as a catalytic raw material or is used for producing lubricating oil through hydrogenation.