With the development of economy society, wastewater treatment has become the focus of people's attention. Montmorillonite has been widely used in the field of wastewater treatment because of its advantages of cheap, easy to obtain and abundant reserves. At present, adsorption materials based on montmorillonite mainly focuses on single modification, such as acid modification, organic modification, but the single modification of montmorillonite has the problem of single function and poor activity. In this paper, the research progress of composite modified montmorillonite, for example, acid-organic modification, inorganic-organic modification and organic anionic cationic surfactant modification are reviewed. The preparation process and adsorption mechanism of composite modified montmorillonite are analyzed. The main research directions in the future are proposed. It is suggested that the main research direction of composite montmorillonite in the future is to synthesize the montmorillonite which can be easily separated from solution and can treat all pollutants in a variety of ways, such as the synthesis of composite montmorillonite with adsorption, photocatalytic and Fenton oxidation ability. This paper may provide some reference for the practical application of montmorillonite in the area of wastewater treatment in future.