Film surface treatment method

The invention belongs to the technical field of printing, and particularly relates to a film surface treatment method. The film surface treatment method provided by the invention comprises the following steps: S1, uniformly mixing a pouring type polyurethane prepolymer, polyester polyol resin and a cross-linking agent to obtain a mixed solution, and pouring the obtained mixed solution into a forming centrifugal machine; s2, placing the liquid dispersion of the nanoscale particles in a spray gun; s3, after the step S1 is poured, the mixed liquid begins to be converted into a gel state and a semi-solid state, and at the moment, liquid dispersions of nanoscale particles are evenly sprayed to the mixed liquid in the gel state and the semi-solid state at a constant speed through a spray gun; s4, the film is cured, and the nanoscale particles are attached to the surface of the film. A particle coating layer is added on the surface of the film, so that the surface tension of the film can be improved, and the propert