The invention discloses a method for preparing a lysozyme composite food packaging film. The method comprises the following steps: 1, respectively preparing a neutral buffer solution of lysozyme and adisulfide bond reducing agent tris(2-carboxyethyl)phosphorus hydrochloride solution, mixing the two solutions to be uniform so as to prepare a composite solution; 2, taking out one part of the composite solution in the step 1 and adding into a packaging bag, enabling the inner wall of the packaging bag to be completely infiltrated by the composite solution, standing, and pouring the composite solution in the packaging bag; 3, drying the packaging bag treated by the step 3, and coating a protein film layer on the inner wall of the packaging bag; 4, repeating the step 2 and step 3, superposingthe protein films layer by layer, and forming the lysozyme composite food packaging film on the surface of the packaging bag. According to the preparation method disclosed by the invention, the surface medium of an ordinary packaging material is changed, the packaging material is attached to the surface of a general package by virtue of adhesion of the proteins, the dense film can be rapidly formed, and the application effect of the packaging film in food preservation is improved.