Hydrotreatment and catalytic cracking combined processing method of residual oil

The invention provides a hydrotreatment and catalytic cracking combined processing method of residual oil. The method comprises the following steps: (1) carrying out the hydrogenation reaction of residual oil, catalytic cracking diesel fuel oil and slurry oil steamed extract in a hydrotreatment device in the existence of hydrogen and a hydrogenation catalyst to obtain gas, naphtha, hydrogenation fuel oil and slurry oil steamed extract; (2) after the gasoline and diesel are steamed out, preprocessing the liquid flow, and reducing the content of metal; (3) facilitating the preprocessed liquid flow to sufficiently contact gas oil and the catalytic cracking catalyst to obtain dry gas, liquefied gas, gasoline and catalytic cracking diesel fuel oil, and separating the catalytic cracking diesel fuel oil; (4) in the existence of the diesel hydrogenation catalyst, facilitating the catalytic cracking diesel fuel oil to sufficiently contact the hydrogen, carrying out the hydrogenation refining reaction, circulating the hydrogenated catalytic cracking diesel fuel oil to the step (3), and circulating the residual catalytic cracking diesel fuel oil to the step (1). The method has the beneficial effect that the yield of light oil is increased.