A novel effective cellulose-based adsorbent was prepared through two common reactions, which included the esterification of sugarcane bagasse cellulose with excess stearic acid and the reaction of grafting polyacrylamide brush by ultraviolet radiation initiation. The adsorbent can effectively adsorb Hg(II) ion from wastewater. The characterization of the adsorbents was conducted by optical microscope (OM), scanning electron microscopy (SEM-EDS) and infrared spectrometry (FTIR). Full kinetic and thermodynamic investigations as well as isotherm analysis were also undertaken. Due to the abundant amide groups, the cellulose-based adsorbents exhibit excellent adsorption performance for the removal of Hg(II) ion from aqueous solution with a maximum adsorption capacity of 178mg/g. Furthermore, the cellulose-based adsorbents can be easily separated from the aqueous solution after adsorption and regenerated using 0.2M HCl solution, which exhibits high adsorption capacity after six adsorption-desorption cycles. In view of the easily-operated cost-effective preparation technique, substantial adsorption efficiency and excellent adsorption recyclability, therefore, the eco-friendly cellulose-based adsorbents could be used for water purification effectively. More importantly, this work improves value of low-cost biomass resources.