The invention discloses a monoclonal antibody resisting the hemocyanin of China prawns, which is secreted by a hybridoma cell with the name of mouse hybridoma cell CS-H and the collection number of CCTCC-C200937. A preparation method of the monoclonal antibody comprises the following steps: obtaining crude extracts of the hemocyanin of the China prawns by extracting the hemolymph of the China prawns through serum centrifugation and overspeed centrifugation; carrying out affinity chromatography and purification for the hemocyanin of the China prawns by utilizing white spot syndrome viruses (WSSV) of prawns; after the verification of electrophoretic analysis and polypeptide mass spectrum analysis, using the hemocyanin subjected to affinity purification as an antigenic immunized Balb/c whitemouse; preparing the hybridoma cell through cell fusion; and screening out the monoclonal antibody by an immunology detection method. The invention provides an important tool for detecting the hemocyanin content change of the prawns in various physiological states and also provides powerful support for researching the effect of the hemocyanin in the non-specific immunity of the China prawns.