The paper mainly research on a method of quickly resolving ofloxacin using molecular imprinting technique. Fe3O4 magnetic nanoparticles coated with silica is acted as the substrate. Chiral reagent is N-octyl-D-glucosamine as monomer, with ofloxacin as the template molecules to prepare magnetic surface molecularly imprinted polymer. The chiral polymer can be combined with dextral ofloxacin, eventually levofloxacin was isolated. Finally by using extermal magnetic field and transmission electron microscopy (TEM), the character of magnetic surface molecularly imprinted polymer is tested, and the levofloxacin is detected by optical rotation.