Abstract: Lithium-ion batteries are widely used in electric vehicles and large-scale energy storage systems. To address the limitations of conventional solid polymer electrolytes, such as low room-temperature ionic conductivity, high crystallinity, and significant solid-solid interfacial resistance, developing composite solid-state electrolytes with high ionic conductivity, enhanced safety, and stable interfaces remains a critical challenge. In this study, a covalently bonded graphene oxide/silicone resin composite solid polymer electrolyte was designed and fabricated. Vinyl-terminated silicone resin (MQ) was copolymerized with methyl methacrylate, acrylonitrile, and vinyl acetate to form MQ-PMAV. This copolymer was then composited with GO and LiTFSI, and the mixture was solution-cast into membranes. Structural characterization indicated that incorporating Si-O-Si silicone units into the polymer backbone, along with GO, reduced crystallinity and improved film-forming ability and mechanical strength. Electrochemical tests showed that the composite electrolyte exhibited a room-temperature ionic conductivity of 1.7×10⁻⁴ S·cm⁻¹ and an electrochemical stability window up to 5.5 V. LiFePO₄|MQ-PMAV-GO|Li cells delivered 95.8% of the theoretical capacity at 0.1C and 50 ℃ after 50 cycles, with nearly 100% Coulombic efficiency. At 0.2C, the capacity retention was 77.6% after 500 cycles. This study offers a novel approach for designing safe, high-performance solid-state electrolytes through the synergistic modification of silicone resin copolymerization and graphene incorporation.