Abstract: Norfloxacin (NOR) is one of the quinolone antibiotics and has been widely detected in the environment. Residual NOR in the aquatic environment may enhance drug resistance and contaminate drinking water, and further threatens human health. Adsorption is an attractive and favorable technique for effective NOR removal. The present study focuses on enhancing the adsorption properties of composite microspheres, which was evaluated by the adsorption capacity of NOR. Six factors were examined to ascertain the effects on the adsorption capacity of composite microspheres, which include mass ratio between biochar and chitosan, degree of deacetylation of chitosan, glutaraldehyde dosage, cross-linking time, cross-linking rate and pyrolysis temperature of biochar. The optimal condition of preparation composite microspheres was deduced by uniform design experiment. The results revealed that the selected factors have significant effects on NOR adsorption capacity. Pyrolysis temperature of biochar, glutaraldehyde dosage and cross-linking rate were the critical factors for preparation of composite microspheres. The adsorption capacity of NOR has achieved 9.51 mg/g under the optimal condition:pyrolysis temperature 300℃, mass ratio 5:1, degree of deacetylation 77%, glutaraldehyde dosage 80 mL, cross-linking rate 150 r/min and cross-linking time 3 h. In addition, composite microspheres have relatively high acid resistance and mechanical strength. In conclusion, composite microspheres could be used as an efficient adsorbent for NOR removal and conveniently separated from aqueous solution after adsorption, which have the potential in environment purification.