Tailoring a robust and slippery tribo-film on polymer-metal interface is a potential approach for improving the tribological performance. In this work, hybrid soft-hard nanoparticles were compounded into polyetheretherketone (PEEK) reinforced with carbon fibers. Effects of nanoparticle combinations on tribological performance of the composites and tribo-film’s functionality were explored. It was demonstrated that hybrid oxide nanoparticles, i.e. Bi₂O₃-SiO₂ and CuO-SiO₂, accelerated formation speed of tribo-films. The soft nanoparticles, i.e. Bi₂O₃ and CuO, having low-melting points expedited tribosintering of wear products on the interface. Moreover, combination of WS₂-SiC nanoparticles resulted in a ‘‘slippery” tribo-film withstanding harsh rubbing conditions. Hard species endowed the tribo-film a high load-carrying capability, while the soft ones imparted the tribo-film an easy-to-shear characteristic. Striking stretching and re-orientation of PEEK molecules in tribo-film were identified and corroborated the ‘‘slippery” characteristic. It is expected that this work can pave a route for developing new self-lubrication composites under extreme running conditions.