In order to improve the deoxidation efficiency and the safety issues caused by the mixing packaging of small deoxidizer and foods, silica sol was prepared by hydrolyzing ethyl orthosilicate and used to coat the iron powder. The iron powder and modified iron powder were respectively molten-blended with the polyamide 6 (PA6) matrix to prepare composite materials. After hot pressing, they were prepared into PA6/iron powder (PA6/Fe) and PA6/modified iron powder (PA6/m-Fe) composite films. The structure and properties of the composite film were characterized by Fourier transform infrared spectrometer (FTIR), thermogravimetric analyzer (TG), differential scanning calorimeter (DSC), universal tensile tester and gas permeation meter. The results showed that in the two composite systems with iron powder and modified iron powder, the dispersibility of modified iron powder in PA6 was better, but the thermal stability of the PA6/m-Fe composite film decreased. Besides, with the increase in the filler (iron powders and modified iron powders), the tensile strength of the composite film showed a trend of increasing first and then decreasing. Its elongation at break decreased and then slightly increased, but overall, it showed a downward trend. With the filler content at 2%, the tensile strength of the composite film reached the maximum value. Compared with the PA6 film, the tensile strengths of the PA6/Fe and PA6/m-Fe composite films increased by 16% and 28%，respectively. The oxygen (O2) transmission coefficient of the composite film showed a trend of first decreasing and then increasing. With the filler content at 2%, the O2 transmission coefficient of the composite film was the smallest. Compared with the PA6 film, the O2 transmission rate coefficients of the PA6/Fe and PA6/m-Fe composite films decreased by 43.2% and 66.1% respectively. During the crystallization process of the composite films, due to the heterogeneous nucleation effect of the modified iron powder, the internal crystallization behavior was improved, which was conducive to the improvement of the structure and performance of the composite films.