A modified Y-type molecular sieve has a unit cell size of 2.420-2.440 nm. It contains a phosphorus content of 0.05-6%, a RE2O3 content of 0.03-10%, and an alumina content of less than 22%, and a specific hydroxyl nest concentration of less than 0.35 mmol/g and more than 0.05 mmol/g. The modified Y-type molecular sieve is used as the active component in a catalytic cracking catalyst. The catalytic cracking catalyst maintains a stable activity for a long time, effectively controls the coke yield and increases the heavy oil utilization.