In order to improve the shielding effectiveness of graphene films, graphene films were prepared by chemical vapor deposition. The effects of hydrogen flow rate, methane flow rate, reaction temperature and reaction time on the electromagnetic shielding properties of the films were investigated. The shielding effectiveness of the film was tested and the preparation process of the film was optimized based on the test results. The results show that when the hydrogen flow rate is 8sccm, the methane flow rate is 15sccm, the reaction temperature is 1030°C, and the reaction time is 30minutes, the shielding effectiveness of the film is 1.2dB (0.3-3000MHz) and the average transmittance is 96%. (400-800nm), the photoelectric comprehensive performance is better.