Abstract: Both hydrotalcite and bentonite are clay materials with special layered structures. Among them, hydrotalcite has good anion exchange properties, while bentonite has good cation exchange properties. In recent years, these two kinds of materials have attracted much attention in water treatment. In this paper, the structure and properties of hydrotalcite and bentonite were summarized, and the application of hydrotalcite, bentonite and their modified materials in the treatment of wastewater containing heavy metal ions such as Pb²⁺, Cd²⁺, Zn²⁺, Cu²⁺ and HAsO₄^2-、Cr₂O₇^2- were introduced emphatically. The results showed that the hydrotalcite roasting products had good adsorption capacity for complex anions (such as HAsO₄^2- and Cr₂O₇^2-) in water, and the adsorption mechanism was mainly interlayer ion exchange. Hydrotalcite after organic or inorganic modification treatment also had good adsorption performance of heavy metal cation (such as Pb²⁺, Cd²⁺, Zn²⁺, Cu²⁺, etc.), and it was likely to exist surface complexation, precipitation, isomorphic substitution, electrostatic attraction and physical adsorption at the same time during adsorption process. Compared with natural bentonite, activated modified bentonite, inorganic modified bentonite, organic modified bentonite or inorganic-organic compound modified bentonite usually had better adsorption performance, and the adsorption was usually physical adsorption, ion exchange, chemical bond or surface complexation. However, the modified hydrotalcite or bentonite was easy to cause secondary pollution to the environment, and it was not conducive to the recycling of adsorbent. Therefore, it was of great significance to research and develop single or composite adsorption materials of hydrotalcite or bentonite with high efficiency and environmental protection.