With the advent of the information age, the proliferation of intelligent devices has also given rise to the issue of electromagnetic pollution. Flexible materials hold significant applications and development prospects in the realm of electronic device shielding. In this study, MnO2 was synthesized through reduction on the surface of carbon fiber paper (CFP), while conductive carbon black (CB) was incorporated into silicone rubber to fabricate a flexible polymer with both surface relative insulation and internal electromagnetic shielding capabilities. Under 1 wt% CB loading, the modified CFP exhibited an electromagnetic shielding performance reaching 33.22 dB, which is 49.5 % higher than that of its original counterpart. By optimizing the thickness of CB within the silicone rubber matrix filling component, impedance matching properties were enhanced for improved material performance. Adjusting medium factors by thickness optimization, at a thickness of 5 mm, the absorption coefficient A for electromagnetic waves entering into the modified CFP increased by 461.7 % compared to that observed in its original form. Furthermore, a contact angle as high as 110° was achieved on the surface of CFP indicating excellent hydrophobicity; moreover, stable adhesion between conductive fillers and surfaces was confirmed through testing procedures conducted thereafter. Additionally, even after undergoing more than ten freezing experiments, over 99 % electromagnetic shielding performance was retained by our developed material ensuring its viability under harsh low temperature conditions.