Abstract: This study presents the interactive cavitation and erosion wear mechanism of water-lubricated bearings. By using computational fluid dynamics method, the dynamic characteristics of vapor, liquid and solid three-phase flow fields (pressure field, velocity field of air bubbles and water vapor volume fraction) was numerically calculated under interactive cavitation effects and erosion wear in water-lubricated bearing. Then the interactive cavitation and erosion wear experiment of three-phase flow was conducted on an MPV-20D friction wear-test machine, and the morphology of wear scars on the specimen surface was observed as well. The results show that the pressure distributions of the whole flow field in water-lubricated bearing was more close to practice after considering the effect of cavitation. Maximal and minimal pressure, maximal velocity and maximal vapor volume fraction on specimen surface all appeared on the neighboring region of cavitation by numerical simulation but basically remained unchanged in other regions. It is indicated that interactive wear was more severe than single wear on the neighboring region of cavitation. Short-range furrows, cavitation pinholes, pockmark cavitation holes and air pits, and the wear scars were presented regularly. The wear scars were consistent with the direction of shaft rotational speed, and the experimental results were in good agreement with numerical calculation, which proved the validity of the theoretical analysis.