To select suitable friction pair materials for high water-based emulsion hydraulic valves,the friction and wear characteristics of the friction pairs composed of ZrO2 and different structural ceramics under high water-based emulsion lubrication were investigated.By using friction and wear tester,the tribological properties of four different ceramic materials (ZrO2,Al2O3,Si3N4,and SiC) sliding against ZrO2 ceramic in a high water-based emulsion medium were studied under different loads and sliding speeds.The wear mechanism of different combinations of ceramic friction pairs was analyzed.The results show that the friction coefficient of each ceramic decreases with the increase of sliding speed in a high water-based emulsion,and the friction coefficient of Al2O3 ceramic is the smallest.The friction coefficient of ZrO2,Al2O3,and Si3N4 is less affected by the load,while the friction coefficient of SiC ceramic increases sharply with the increase of load.The wear volume of each ceramic increases with the increase of velocity and load,among which the wear volume of Al2O3/ZrO2 ceramic friction pair is the smallest,and its wear mechanism is mainly abrasive wear and micro fatigue wear.Research shows that under different working conditions,Al2O3 and ZrO2 ceramic pairs have the lowest friction coefficient and wear volume,which are more suitable as friction pair materials for high water-based emulsion hydraulic valves.