The L zeolite synthesized on kaolin microspheres was modified to reduce its potassium oxide content and improve its silicon-aluminum ratio. The amount, temperature and time of ammonium sulfate during ion exchange were optimized, the effects of roasting on silicon-aluminum ratio and crystallinity were investigated, and ion exchange, citric acid treatment and water vapor roasting were combined to improve the silicon-aluminum ratio of zeolite. The results showed that the optimal reaction conditions during ion exchange were zeolite:water:ammonium sulfate ratio of 1g:10mL:1g, reaction temperature 80 °C, reaction time 2h. Ion exchange, citric acid treatment combined with hydrothermal roasting can significantly improve the silicon-aluminum ratio of zeolite while maintaining the integrity of the crystal structure, and when the citric acid concentration is 0.10 mol/L, the crystallinity of the three-cross lemon three-baked (E) sample is 82%, and the silicon-aluminum ratio reaches 13.60.