Despite the fact that PEDOT:PSS has been successfully used in the field of flexible electronics, some of its applications in the domain of rigid conductive coating have been limited by the pricey cost and subpar mechanical properties (hardness, adhesion, and moisture absorption) of the commercially available Clevios™ PH 1000, as well as the poor conductivity, film formation, and mechanical properties of the self-made PEDOT:PSS. In the process of investigating the low-cost preparation of PEDOT-based conductive polymer coatings, we discovered that self-made PEDOT:PSS, a waterborne epoxy resin, and a bio-based epoxy curing agent can be blended uniformly to produce good film-forming conductive coatings. Later, the addition of KH560-modified nano-SiO₂ further improved the coating’s hardness while ensuring a modest increase in conductivity. Meanwhile, the inadequacies of the epoxy resin, which are not UV-resistant, were considerably improved by the synergistic action of PEDOT:PSS and the modified SiO₂. The result is a low-cost method designed for creating conductive coatings that are UV-resistant and may be utilized for electromagnetic, electrothermal, and antistatic shielding applications. Such a PEDOT:PSS/epoxy composite system and its design approach will broaden the scope of PEDOT:PSS’s application and will inspire future research in and practical implementations of PEDOT:PSS-based conducting coatings.