The work aims to develop a new type of active packaging film with excellent physicochemical properties for the preservation of grass carp. The PE-BW-SiO2 composite packaging film was produced by melt blending and granulation blown film process with polyethylene as the base film material, and beeswax and nano-SiO2 as the active ingredients. Meanwhile, the mechanical, barrier and hydrophobic properties of the film were determined and its freshness preservation effect on grass carp under 4 ℃ storage conditions was investigated. The mechanical, barrier and hydrophobic properties of the packaging film were improved by the addition of BW-SiO2. Among them, the packaging film with 2% BW-SiO2 achieved the best mechanical, barrier, and other comprehensive properties. After the grass carp packed in different packaging films was stored at 4 ℃ for 11 days, it was shown that compared with the pure PE packaging film, the composite PE packaging film with BW-SiO2 active ingredient had a better preservation effect on the grass carp, and it could reduce the water loss and lipid oxidation reaction of the fish, effectively slowing down the corruption and deterioration and prolonging the storage period. PE-BW-SiO2 composite packaging film has excellent physicochemical properties and a high capacity to preserve freshness. It effectively blocks external water and oxygen penetration, which slows down water loss and lipid oxidation reactions, thereby preventing microorganisms from growing. This packaging film can extend the shelf life of grass carp up to 11 days at 4 ℃ by effectively slowing down the spoilage process.