In this paper,a FCC co-catalyst for enhancing the light oil production was prepared by thesol-gel method,and its effect on the performance of residue cracking catalysts was evaluated in a CCFFBreactor.The test results indicated that the liquid product yield increased obviously,after the surface ofFCC equilibrium catalyst was impregnated with the co-catalyst.The yields of dry gas,slurry and cokedecreased,while the diesel yield changed slightly.And the crackability of residue was increased;therate of coke deposition on catalyst surface was decreased,with the thermal cracking reactions inhibited.All these results showed that the co-catalyst could improve the density of acid sites and change thecatalyst acidity,which could promote to prolong the catalyst activity by depositing the co-catalyst onthe surface of FCC equilibrium catalysts. In this paper, a FCC co-catalyst for enhancing the light oil production was prepared by thesol-gel method, and its effect on the performance of residue cracking catalysts was evaluated in a CCFFB reactor. The test results indicated that the liquid product yield increased , after the surface of FCC equilibrium catalyst was impregnated with the co-catalyst. The yield of dry gas, slurry and cokedecreased, while the diesel yield changed slightly. And the crackability of residue was increased; the rate of coke deposition on catalyst surface was decreased, with the thermal cracking reactions inhibited. All these results showed that the co-catalyst could improve the density of acid sites and change the catalyst acidity, which could promote to prolong the catalyst activity by depositing the co-catalyst on the surface of FCC equilibrium catalysts.