A catalyst of cracking petroleum contains Y-type zeolite, ZSM-5 zeolite and carrier. It features that said Y-type zeolite is prepared from superstable rare-earth Y-type zeolite and high-silica Y-typezeolite prepared by liquid-phase chemical process and with crystal cell constant less than 2.456 nm in a weight ratio of (0.5-1) : (1 : 1.5), and said ZSM-5 zeolite is a hydrogen-type one with Si-Al ratio of 80-800. Said catalyst can be used for catalytic cracking reaction of heavy oil for higher octane number of gasoline and higher yield of light oil.