Catalytic cracking and catalytic gasoline hydrogenation combined process

The invention discloses a catalytic cracking and catalytic gasoline hydrogenation combined process. The process comprises: adjusting the operating conditions of an FCC (fluid catalytic cracking) device fractionating tower, and conducting cutting pre-separation on FCC gasoline in the fractionating tower to obtain light fractions and heavy fractions; subjecting the light fractions to alkali-free deodorization, then leaving the light fractions and thermocatalytic diesel oil to enter a hydrogenation prefractionator together to separate light gasoline and medium gasoline; and making the medium gasoline pass a prehydrogenation reactor and a hydrodesulfurization reactor in order to perform moderate selective hydrogenation, subjecting the heavy fractions to deep selective hydrogenation, and mixing the two parts of refined distillate oil with the refined light gasoline so as to obtain a clean gasoline product or a blending component. According to the process provided in the invention, the equipment energy consumption is reduced significantly, the gasoline octane number loss is small, and the gasoline product quality can meet quality requirement for a sulphur content of less than 10 micrograms/g, and the economic benefits of oil refining enterprises can be improved.