The disclosure relates to a new type of biomimetic affinity purification material and the use thereof in purifying chitosanase, and belongs to the field of industrial biotechnology. The affinity ligand of the biomimetic affinity material is chitobiose, the connecting arm is cyanuric chloride, and the basic medium is activated agarose 6B. The dissociation constant (Kd) and maximum binding capacity (Qmax) of biomimetic affinity material are 24.2 μg/mL and 24.1 mg/g, respectively. A biomimetic affinity purification method for chitosanase is established using the biomimetic affinity material. The method can produce high purity chitosanase with high efficiency and low cost, and has good industrial application potential.