Hexagonal Boron nitride (BN) can be used as a lubricant additive, which can dramatically reduce friction energy. However, due to the accumulation of BN in the water-based lubricants and the difficulty of entering the friction contact area, the tribological performance of BN becomes worse. To address this issue, the atomically thin hydroxylated boron nitride nanosheets (HO-BNNS) were successfully prepared. The thickness of HO-BNNS is only 0.6-0.8 nm. Meanwhile, the HO-BNNS has excellent dispersion stability in water-based lubricants because of the hydroxyl group on the surface of HO-BNNS. The as-prepared HO-BNNS exhibits unique friction properties as a water-based dispersible lubricant additive. Additionally, the average wear scar diameter, average friction coefficient, and mean wear volume of HO-BNNS/water-based (0.05 wt%) drop by about 64.7%, 60%, and 95.73%. Finally, the introduction of HO-BNNS can well control the temperature of water-based lubricant.