Self-lubricating spherical plain bearings are deemed key components used for aerospace engineering, in which their performance depends primarily on self-lubricating materials between the inner and outer rings. This study investigates the synergistic effects of two fillers on the mechanical and tribological properties of epoxy-based composites. The combination of PEEK and PTFE resulted in an epoxy composite exhibiting a wear rate as low as 4.1×10⁻⁶ mm³/(N·m) and a friction coefficient of 0.09 under 140   MPa. PEEK enhanced the toughness, deformation resistance, and friction-reducing capacity of the epoxy matrix. FEM analysis indicated that the inclusion of PEEK reduces plastic strain accumulation and alleviates friction-induced stress. XPS results confirmed the formation of Fe-F bonds, which promotes the development of a high-quality fluorinated transfer film. MD simulations revealed that PEEK facilitates the formation of it. These findings demonstrate a synergistic interaction between PEEK and PTFE in enhancing tribological performance, providing theoretical support for their use in self-lubricating bearings.