Method for preparing fluid catalytic cracking (FCC) gasoline small-molecule sulfur densification catalyst

The invention relates to a method for preparing a fluid catalytic cracking (FCC) gasoline small-molecule sulfur densification catalyst. The method comprises the following steps of: mixing deionized water, sodium hydroxide, an aluminum source with a template; adding a silicon source; ageing; and performing hydrothermal crystallization, wherein the template is a multiple cationic polyquaternium surface active agent; performing suction filtration, washing, drying and roasting on products obtained after the hydrothermal crystallization to obtain Na-type meso/microporous Zeolites Socony Mobil-5 (ZSM-5) zeolite raw powder; performing ammonium exchange, suction filtration, drying and roasting on the Na-type meso/microporous ZSM-5 zeolite raw powder to obtain H-type meso/microporous ZSM-5 zeolite; preforming, crushing and screening to obtain a carrier of the FCC gasoline small-molecule sulfur densification catalyst; loading an active component onto the carrier by adopting an equivalent-volume impregnation method; and drying and roasting to obtain the catalyst. By adopting the catalyst, sulfur compounds, such as low-boiling point sulfur alcohol and thiophene, can be converted into high-boiling point sulfur compounds, and the high-boiling point sulfur compounds are transferred into heavy-fraction gasoline to perform selective hydrodesulfurization on the heavy-fraction gasoline, and the two components are blended to obtain clean gasoline.