The invention relates to a catalytic cracking catalyst, a preparation method and applications thereof, wherein the catalyst comprises 10-50 wt% of a modified Y-type molecular sieve, 10-40 wt% of an alumina binder (calculated as alumina), and 10-80 wt% of clay (calculated as dry base), wherein the modified Y-type molecular sieve comprises (calculated as the weight of the dry base of the modified Y-type molecular sieve) 5-12 wt% of rare earth elements (calculated as oxide), 0.1-0.7 wt% of sodium oxide, 0.1-2.5 wt% of gallium oxide, and 0.1-2.5 wt% of zirconium oxide, the total pore volume of themodified Y-type molecular sieve is 0.33-0.39 mL/g, the pore volume of the secondary pores with a pore size of 2-100 nm accounts for 10-25% of the total pore volume, the cell constant is 2.440-2.455 nm, the lattice collapse temperature is not lower than 1050 DEG C, the non-skeleton aluminum accounts for not more than 20% of the total aluminum content, and a ratio of the amount of the acid B to theamount of the acid L in the amount of the strong acid is not less than 3.0. According to the invention, with the application of the catalyst in processing hydrogenation of LCO, the LCO conversion efficiency is high, the coke selectivity is low, the yield of gasoline rich in aromatic hydrocarbon and the yield of propylene are high, and the concentration of propylene in liquefied gas is high.