PEI-SBC/Mt composite spheres were prepared by simple coagulation bath method using bagasse cellulose (SBC) and montmorillonite (Mt) as raw materials and calcium carbonate as porogenic agent. The structures of the prepared spherical adsorbents were characterized by FTIR, SEM and XRD, and the adsorption behaviors of the adsorbents on cadmium ion Cd(II) in simulated wastewater were systematically investigated. The results showed that the proposed secondary kinetic model and Langmuir model could accurately describe the adsorption process, and the maximum adsorption amount of Cd(II) by PEI-SBC/Mt at the temperature of 25 ℃, pH=6 and the initial mass concentration of Cd(II) was 600 mg/L , indicating that the adsorption process was single-molecule chemisorption, and the addition of PEI provided a more efficient way for the adsorbent to adsorb Cd The addition of PEI provided more active sites for the adsorbent to adsorb Cd(II). In addition, the adsorbent was reusable and its adsorption capacity only decreased from the original 94% to 79.8% after five cycles of adsorption and desorption.