Ammonium ion exchange method for Y-type molecular sieve

The invention discloses an ammonium ion exchange and ultra-stabilization method for a molecular sieve, which comprises the following steps: mixing Na-type molecular sieve and ammonium salt evenly according to a weight ratio of the molecular sieve to the ammonium salt of 1: (0.1-1.0), heating the mixed material to between 90 and 300 DEG C, keeping the temperature for at least 1 hour in a rotary orstatic state, cooling the mixed material to the room temperature, then mixing and beating the mixed material and deionized or decationized water according to a weight ratio of the molecular sieve to the water of 1: (1-10), filtering the slurry, and drying a filter cake to obtain the molecular sieve after ammonium ion exchange; and baking the obtained molecular sieve after the ammonium ion exchange for at least 0.5 hour at the temperature of between 400 and 700 DEG C under complete water vapor atmosphere to obtain the ultra-stabilized Y-type molecular sieve. The ammonium ion exchange and ultra-stabilization method prov