In order to study the lubricant for preparing the ultrafine grained bulk aluminum alloy by the helical channel angular pressing process,graphite and molybdenum disulfide with different mass fractions were added to the lithiumbased extreme pressure(EP) grease.With H13 steel and aluminum alloy 2024,7075 as the friction pairs,the friction and wear experiments of surface on surface contact with medhigh pressure were conducted at the reciprocating experimental platform to study the friction reducing and antiwear properties of different greases.The results show that the addition of solid lubricant in EP grease can improve the friction reducing and antiwear ability in the process of large plastic deformation and change the friction and wear form.The main wear patterns are occlusive adhesion wear and abrasive wear without solid lubricant,and slight adhesive wear with solid lubricant.Compared with molybdenum disulfide,graphite shows better lubrication performance since the hexagonal layered inner structure play a better supporting role.The addition of graphite solid lubricant is related to the friction and wear mechanism of the material.The appropriate amount of graphite is from 10% to 20%.The friction and wear mechanism for the softer aluminum alloy 2024 against H13 steel is main adhesive wear,and it is needed to add more graphite to fill the furrow formed by adhesive wear,while friction dorm for harder aluminum alloy 7075 against H13 steel is boundary friction,and the amount of added graphite is relatively small.