Carbon quantum dots (CQDs) and choline amino acid ionic liquid (ILs) were prepared from biomass materials, and CDILs composite lubricant was obtained by modifying CQDs with ILs. The structure and morphology of CDILs were characterized by FTIR, NMR and TEM, and the effects of the addition of CQDs and CDILs on the tribological properties of water-based lubricants and the related friction mechanism were studied using the friction coefficient and volume wear rate as the indexes. The results show that the friction coefficient and volume wear rate of the water-based composite lubricant are 0.14 and 1.91×10-9 mm3/ (N·m), respectively, when the addition of CDILs is 0.3 wt%, which are 33% and 36% lower than that of pure water. In the friction process, CDILs plays an excellent synergistic role in forming a continuous, uniform and firm self-lubricating transfer film on the metal friction surface, preventing direct contact with the grinding surface, and making its composite lubricant have more lasting anti-friction and wear resistance.