In current work, by an ordinary one-step hydrothermal strategy, the covalently bonded graphitic carbon nitride/molybdenum disulfide (g-C3N4/MoS2) nanocomposites were successfully synthesized. SEM, TEM analyses evidenced the well distribution of MoS2 nanoparticles on g-C3N4. The covalent bond (C-S bond) between two-dimensional (2D) g-C3N4 and zero-dimensional (0D) MoS2 were confirmed by FTIR and XRD. Furthermore, the average friction coefficient and wear rate of g-C3N4/MoS2 nanocomposites at 0.20 wt % concentration could separately reach up to 27.86 % and 70.87 % reduction by comparing pure oil, benefiting from synergistic lubrication of g-C3N4 nanosheets plus spherical MoS2. In the work, novel guidance will be provided for the potential application of multi-dimensional g-C3N4-based nanocomposites in lubricating field.