Provided are a catalytic cracking catalyst and a preparation method therefor. The catalyst contains a double-pore distributed silicon aluminum material and a molecular sieve. The probable pore diameters of the pores with smaller pore diameters of the silicon aluminum material are 2-10nm, and the probable pore diameters of the pores with larger pore diameters are10-25nm. With the total amount of the catalysts as a reference, by weight, the content of the double-pore distributed silicon aluminum material is 1-52%, the content of clay is 9-60%, the content of phosphorus is 0-8% in terms of P2O5, the content of rare earth metal is 0-3% in terms of Re2O3, the content of binding agents is 19-70%, the content of the molecular sieve is 20-70%, and the molecular sieve is a Y-type zeolite. The catalyst has high anti-metal-pollution ability, high heavy oil cracking ability and high liquid yield and can raise quality of gasoline in cracked products greatly.