In order to explore the tribological law of hydraulic components in high waterbased emulsion medium,the Rtec friction and wear tester was used to simulate the friction and wear changes of the contact pairs of hydraulic components in different volume fraction of high waterbased emulsion under different load and frequency conditions.Based on the measured friction coefficient and the wear marks measured by the white light interference threedimensional surface profilometer,the lubrication behavior and the friction and wear law of hydraulic components in different volume fraction of high waterbased emulsion were analyzed.The results show that the friction coefficient and wear loss of high waterbased emulsion media are significantly lower than that of pure water media.With the increase of volume fraction of high waterbased emulsion,the friction coefficient is first decreased and then increased,and the friction coefficient is the minimum when the volume fraction is 5%.With the increase of volume fraction of high waterbased emulsion,the wear loss is decreased,and the decrease range tends to be stable when the volume fraction reaches 8%.Considering the friction coefficient and wear loss,the high waterbased emulsion of 8% volume fraction has the best antiwear and friction reducing effect,which can form a effective lubricating film,plays the role of bearing and lubricating and improves the mechanical efficiency and service life of hydraulic components.