Abstract: Aircraft, satellites and other aircraft with key electronic components, are susceptible to interference from strong electromagnetic field. And some structures of aircraft need to meet mechanical requirements such as large deformation and stretchability in work. Therefore, highly conductive and stretchable electromagnetic shielding materials have attracted widespread attention. Using graphene oxide as raw material and through casting method and high-temperature graphitization treatment, a highly conductive and flexible graphene film compressed with four layer porous fims (GP-4) with the thickness of 13.5 μm was prepared, whose electrical conductivity and electromagnetic shielding efficiency were 6010 S/cm and 68.4 dB, respectively. Using polydimethylsilane (PDMS) as the base, GP-4/PDMS-50.5 composite film with stretchable bilayer structure was prepared, whose elongation was as high as 50.5%. When the axial tensile strain of the composite film is 50.5% and the number of stretching cycles is 500, the composite film could still maintain excellent conductivity and electromagnetic shielding performance. Among them, the resistance of the composite film is 1.04 Ω and 1.06 Ω, keeping constant with the GP-4 film almost. The electromagnetic shielding efficiency of the composite film is as high as 68.5 dB and 67.7 dB. These excellent properties indicate that GP-4/PDMS-50.5 composite film has great application prospects in the electromagnetic shielding field of flexible electronic devices.