In order to explore the influence of the choice of materials and surface treatment techniques on the friction and wear performance of key components of hydraulic actuators under different lubrication conditions,orthogonal friction tests were conducted on the inner wall of the piston- hydraulic cylinder and the piston rod-end cap under three lubrication conditions of dry friction,lack of oil lubrication and full oil lubrication.The effects of lubrication on the wear performance of the two applications were analyzed by testing the friction coefficients,wear amounts and surface morphology of different friction pairs before and after wear.Affected by the surface texture of the guide belt and the self-lubrication properties of tungsten carbide,the friction coefficient of the piston- hydraulic cylinder mating interface with 40Cr-guide friction pair and the piston rod-end cap mating interface with tungsten carbide-guide friction pair is lower under dry friction and lack of oil lubrication.Under the condition of sufficient oil lubrication,due to the formation of oil film at the contact interface,the frictional wear trend is opposite to the above results,and the coefficient of friction is lower for the piston- hydraulic cylinder mating interface with Cu-40Cr friction pair and for the piston rod-end cap mating interface with Cu-tungsten carbide friction pair.