The adsorption properties and mechanism of AFB1 on Ca-montmorillonite with different layer charge numbers were studied by using Ca-bentonite from Inner Mongolia, Xinjiang and Liaoning as the research object. The mineralogical properties, physical and chemical properties of bentonite from different producing areas and the adsorption kinetics and isothermal adsorption of AFB1 by Ca-montmorillonite were studied by using X-ray diffractometer, infrared spectroscopy, high performance liquid chromatography and other testing methods. The results show that the bentonite from Inner Mongolia(N-Mt) with high Ca-montmorillonite content, large specific surface area and high layer charge numbers has better adsorption properties. When the initial concentration is 1.5 mg/L and the amount of adsorbent is 5 mg, the saturated adsorption capacity of AFB1 is 1.153 mg/g, and the adsorption process is less affected by pH value. The adsorption behavior of AFB1 on Ca-montmorillonite conforms to both the pseudo-first-order kinetic model and the pseudo-second-order kinetic model, which indicates that the adsorption process may involve both physical adsorption and chemical adsorption, and the adsorption between Ca-montmorillonite and AFB1 occurs at both interlayer and interlayer levels. The adsorption between Ca-montmorillonite and AFB1 is mainly due to electron donor-acceptor binding and ion-dipole interaction between Ca-montmorillonite and AFB1 molecules. The isothermal adsorption of AFB1 by Ca-montmorillonite is more in line with the Langmuir model, which is a monolayer adsorption.