Abstract: This study aimed to synthesize nano silver using natural plant polysaccharides as reducing agents and integrated them into a bio-based composite packaging system to create a novel green food packaging material with excellent material properties and preservation performance. Sweet corncob polysaccharide-nano silver (SCP-AgNPs) were synthesized by green methods and loaded onto films with sweet corncob polysaccharides as the carrier. The optimal preparation process of the film was determined through single-factor and response surface experiments with tensile strength as the response value. The structure of the film was characterized and its performance was tested. The preservation ability of the film for pork was explored through pH, pressure loss, volatile basic nitrogen content, thiobarbituric acid reaction value, and silver residue. The results showed that the tensile strength of the film was the highest, reaching (14.18±0.47) MPa. When the addition amount of polyvinyl alcohol was 2.1 g, that of chitosan was 2.1 g, and that of SCP-AgNPs was 10 mg. Under these conditions, the SCP-AgNPs film prepared exhibited a smooth surface morphology, good mechanical properties and antibacterial effects, weak water absorption, certain water solubility and antioxidant capacity. Meanwhile, the components of the SCP-AgNPs films were well dispersed and had barrier properties against moisture, light and gas. The tensile strength, elongation at break, air permeability, oxidation resistance and antibacterial property of the film had been significantly improved due to the addition of SCP-AgNPs. The results of the pork storage experiment demonstrated that the pork preservation performance and sensory evaluation score of the SCP-AgNPs film were significantly better than those of the without SCP-AgNPs film. The addition of SCP-AgNPs prolonged the preservation period by 2 to 4 days. Meanwhile, the residual silver content complied with the safety standards. SCP-AgNPs film can effectively extend the preservation period of pork due to its excellent physical properties and pork preservation capacity. This provides a theoretical basis for the practical application of the film and also offers new ideas for the green preservation of pork.