Abstract: In order to prepare a composite film with good mechanical properties and preservation properties, different bleached shellac/sodium alginate composite films were prepared by taking 1.5% sodium alginate as the base film solution, adding different concentrations of bleached shellac particle emulsion, and loading antioxidant tocopherol. Then the mechanical properties and permeability were compared, and the structure was characterized through FTIR spectroscopy analysis and SEM testing. The differences in preservation effects on cold fresh meat were also compared. The results showed that the composite film with 5% bleached shellac content had better properties, including mechanical properties, 37.37% reduction in transmittance and 43.00% increase in utraviolet ray barrier compared with PE film, and better CO₂/O₂ selectivity. And the microstructure characterization of the composite films were mutually confirmed with their performance. Using this film to pack chilled pork for preservation can effectively reduce the TVB-N content, drip loss, pH value and metmyoglobin content, and increase the shelf life to 9 days. This work has certain reference significance for the development of edible film and benefits for slowing down the spoilage of chilled pork during storage, protecting the color and taste of pork, and enhancing its nutritional value.