Platelets with high aspect ratio as fillers in polymer coatings increase the diffusion path of gases and thus contribute to corrosion resistance. Here we demonstrate that the same platelets can improve tribological properties and thus open a new way to design multifunctional polymer coatings. Improved corrosion resistance, low friction, and low wear are reported for polyimide composite coatings filled with a combination of boron nitride (BN), pigment platelets, perfluoropolyether (PFPE), and Si3N4 particles. In order to explore contributions of different fillers to the tribological performance, polyimide coatings with different filling protocols are prepared and investigated with respect to tribological mechanisms. The synergy of four components leads to the excellent tribological performance of the fully formulated coatings, while they cannot impart significant improvement in both friction and wear performance when used separately. Among the four filling components, PFPE and its bonding to the platelets’ surface contribute greatly to the coatings’ overall tribological properties, while BN and Si3N4 particles help in the formation of transfer films and improving the interfacial bonding of the transfer film to the counter body. These mechanisms are discussed based on tribological tests and characterization of worn surfaces.