Abstract: Based on the properties of bentonite, the deep processing technology and application of montmorillonite were discussed on the basis of systematically expounding the composition, structure and physical and chemical properties of montmorillonite. Research showed that montmorillonite has excellent controllable retrofit, and can be exfoliated and dispersed to prepare gel by sodium modification, organic intercalation and pillared montmorillonite can be prepared by cationic exchange modification, and organic monomer and metal oxide precursor can be further introduced into montmorillonite interlayer domain. Montmorillonite/polymer nanomaterials and oxide/montmorillonite nanocomposites were prepared by in-situ polymerization and hydrolysis, dehydroxyl and nucleation crystallization. Zeolites and albites can be synthesized at low temperature and atmospheric pressure by using the characteristics of large specific surface area and strong chemical reaction activity of montmorillonite. A series of new functional montmorillonite materials can be prepared through controllable retrofit and deep processing, and have a wide range of applications in strategic new industries.