The 2D nanomaterials have achieved the superlubrication property whatever in solid or liquid lubrication in recent years. However, whether or not the nanosheets can stably disperse in oils and smoothly enter into the asperity of friction pairs is crucial for exerting the function of antifriction. The structure of 2D QDs is desirable for addressing these issues due to its smaller 3D size. In this study, we developed a facile preparation process for WS2 QDs with uniform 2 nm size from nanosheets via hydrothermal-assisted grinding approach. The structure of the as-obtained WS2 QDs was determined by a series of characterizations. The results showed that the as-obtained WS2 QDs exhibited the typical spectrum features of nanosized quantum dot. The results of the tribological performance in grease verified that the average friction coefficient (ACOFs) and wear volume (AWVs) were decreased by 7.89% and 63.90% relative to grease, respectively, exhibiting a preferable friction reducing and wear resistance.