In this work, a novel water-based lubricating additive of graphene oxide@polytetrafluoroethylene (GO@PTFE) composite was synthesized by electrostatically encapsulating PTFE with GO nanosheets. The fabrication of GO@PTFE composite solves poor dispersion stability and wettability of PTFE. Through investigating water-lubricating performance of tribo-pairs (zirconia ball and brass block) as typical bearing materials, the results indicate that friction coefficient and wear rate of GO@PTFE additive are respectively 77% and two orders of magnitude lower than those of pure water, and also lower than those of PTFE and GO alone. The influences of additive concentration, load and velocity on tribological properties were studied in detail. Mechanism analysis has shown that the synergistic effect and formation of uniform lubricating film is the main reason for its excellent performance.