To explore the tribological properties and synergistic mechanism of graphene oxide(GO) and zinc dialkyl dithiophosphate(ZDDP). GO and ZDDP were selected as additives, zetasizernano, fourier transform infrared spectroscopy(FTIR) and atomic force microscopy(AFM) were used to characterize the particle size, functional group and layer number of GO. The preliminary study on the friction and wear properties of GO using the four-ball testing machine, and the friction and wear properties of ZDDP and mixed additives of ZDDP and GO on the base oil were investigated. The diameter, morphology and surface elements of grinding spots were analyzed by metallographic microscope, scanning electron microscope(SEM) and energy spectrometer. Effects of GO and ZDDP on film forming characteristics of the base oil under starvation condition were studied with a ball-disk optical interferometer. GO shows good anti-wear performance. When the mass fraction of GO is 0.03%, the anti-friction and anti-wear performance of the oil is the best, the friction coefficient is reduced by 31.9%, and the wear scar diameter is by about 20.1%. When 2.5% of ZDDP is added to the base oil PAO10, the friction coefficient of the oil is 0.067, and the wear scar diameter is 407 μm, which is reduced by 18.5% and 41.86% respectively. When the mass fraction of ZDDP and GO is 2.5% and 0.01% respectively, the anti-friction performance of the oil is effectively improved, and the friction coefficient is about 0.056, which is reduced by about 16.7%. At the entrainment speed of 90 mm/s and 180 mm/s, central film thickness of the base oil can be increased, and oil starvation can be alleviated when ZDDP and the addition of ZDDP and GO was added. GO has excellent anti-friction and anti-wear properties. The anti-friction and anti-wear properties of the friction pairs can be improved by using blends of GO and ZDDP due to better synergistic role. Starvation conditions in the contact zone can be alleviated in different degrees when GO, ZDDP and blends of GO and ZDDP is added to the base oil PAO10.