In order to overcome the process insufficiency and safety problems caused by the mixing of oxygen absorber sachets and food, nano zero-valent iron (nZVI) was prepared by hydrothermal method, and it was blended with polyvinyl alcohol (PVA) solution to prepare PVA/nZVI composite films with better structure and oxygen barrier performance. The structure and properties of the membrane were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TG), and differential scanning calorimetry (DSC). The results showed that PVA and nZVI were well combined in the composite film. After adding nZVI, the glass transition temperature (Tg) of the composite film increased and the thermal stability decreased. With the increase in nZVI content, the mechanical properties of the composite film first enhanced and then weakened, and the tensile strength and elongation at break of the composite film reached the maximum when the nZVI mass fraction was 2%. The oxygen permeability coefficient of the composite membrane decreased first and then increased with the increase in nZVI content, and the oxygen permeability coefficient of the composite membrane was the smallest when the nVZI mass fraction was 3%. In the composite film, a strong interaction could be formed between the hydroxyl groups of nZVI and PVA, which improved the structure and properties of the composite, but the valence iron catalyzed by the partial oxidation of nZVI and its surface accelerated the thermal degradation of PVA.