Abstract: Using nano-Fe₃O₄,chitosan as material,modified magnetic chitosan was prepared by inverse suspension cross-linking method and triethylamine as modifier. The adsorption performance of modified magnetic chitosan to carmine pigment was evaluated. The effects of time,pH value,temperature and initial concentration of carmine on the adsorption efficiency of modified magnetic Chitosan on carmine solution were investigated. The adsorption kinetics model,adsorption isotherm model,adsorption thermodynamics and adsorption regeneration performance were preliminarily discussed. The results showed that when pH=3,adsorption time was 270 min,temperature was 50℃,initial concentration was 100 mg/L,the adsorption rate of modified magnetic chitosan to carmine red solution could reach 96.72%. The adsorption kinetics data of the adsorbed carmine solution accorded with the pseudo-second order kinetic model,and the adsorption isotherm data conformed to the Langmuir model. The thermodynamic data were fitted to obtain ΔH>0,ΔS>0,and ΔG<0,and it was found that the reaction was an endothermic reaction. After three adsorption-analysis experiments,the adsorption rate and resolution were still above 40%.