Chitosan coated bentonite (CCB) was prepared by microwave irridiation, original bentonite as raw materials and chitosan as modifier. The adsorption performance in acid scarlet dye solution was discussed. Firstly the optimum adsorption conditions: concentration of chitosan of 35 g/L, bentonite quality and chitosan solution volume rate of 0.7(g/L), microwave time of 17 min, infilltration time of 50 min, deacetylation degree of chitosan of 85%, soil particle size of 15 mm, pH of 5, dosage of CCB of 20 g/g, stirring speed of 300 r/min, centrifugal time of 15 min, and stirring time of 35 min, were investigated by single factor experiment. And the maximum adsorption rate reached to 96.2%. Subsquently, all the effect tendencies of the physicochemical parameters of the preparation and adsorption were studied on the optium experimental condition, which would provide reference data for the subsequent pilot test. The results suggested that CCB was a promising sorbent to remove organic contaminants and might be utilized to purify water contaminated by organic compounds.