The invention relates to a heavy oil catalytic cracking catalyst, which mainly comprises, by mass, 5-30% of a high hydrothermal stability silicon-based mesoporous material, 20-50% of a zeolite molecular sieve, 20-60% of clay, and 5-30% of a binder, wherein the silicon-based mesoporous material is treated for 8-12 h at a temperature of 100-150 DEG C with a tetrafluoroborate anion imidazole-based ionic liquid with a carbon atom number of 4-12, and is calcined for 2-6 h at a temperature of 400-600 DEG C. According to the present invention, under the conventional heavy oil catalytic cracking operation conditions, the heavy oil conversion rate and the light oil yield of the catalyst are increased, and the yields of coke and heavy oil are decreased.