Abstract: Embedding nanofillers into a polymer matrix is an effective strategy to enhance the barrier properties of anticorrosive coatings. To improve the overall performance of the coating, this study developed an epoxy resin-based dual nano filler composite coating by synergistically modifying an epoxy coating with two nano fillers: 3 aminopropyltriethoxysilane modified graphene oxide (KGO) and nano anhydrous calcium sulfate particles. The morphology and elemental composition of the composites were characterized by Fourier transform infrared spectroscopy and transmission electron microscopy. Scanning electron microscopy, electrochemical tests, and adhesion measurements were used to investigate the coating’s surface morphology, mechanical properties, and anticorrosion performance. The results show that the synergistic interaction of the two nanofillers forms a dense, well structured nanonetwork, which markedly enhances both the corrosion resistance and mechanical strength of the coating. Electrochemical impedance spectroscopy revealed that the impedance modulus of the dual nanofiller coating exceeds that of a conventional coating by three orders of magnitude, reaching 1.25×10¹⁰(Ω·cm²). Compared with pure epoxy, the coating’s adhesion, hardness, and tensile strength improved by 127%, 315%, and 202%, respectively. Moreover, after long-term immersion in a simulated corrosive environment, the coating still maintained excellent anticorrosive performance, demonstrating its potential as a high performance anticorrosive material.