The invention discloses a method for preparing a Cr/CrN/Cu-TiN film on the surface of a stainless steel operation instrument, and relates to a method for preparing a film on the surface of a stainless steel instrument, aiming at solving the problem that patients suffer from cross infection in operation as body fluid, such as blood largely adhered to a conventional operation instrument, so that the operation instrument cannot be completely cleaned, sterilized and disinfected. The method comprises the following steps: I, performing ultrasonic washing; II, performing chemical etching; III, performing Ar ion sputter cleaning; IV, performing Cr ion sputter cleaning; V, depositing a Cr layer; VI, depositing a CrN layer; VII, depositing a Cu-TiN layer, that is, the preparation for the Cr/CrN/Cu-TiN film is completed on the surface of the stainless steel operation instrument. The method has the advantages that the thickness of the Cr/CrN/Cu-TiN film is greatly smaller than that of a conventional Cr or Ni film, so that the cost is saved, and the anti-adhesion and antibacterial properties are improved. The method is mainly used for preparing Cr/CrN/Cu-TiN films on the surfaces of the stainless steel operation instruments.