7055 aluminum alloy was treated by singlestage solution,twostage solution and high temperature preprecipitation respectively.The hardness of the samples after different solution treatment was measured,and the surface roughness of the samples after grinding with different sandpaper was measured.The friction and wear properties of the samples after grinding with different sandpaper against GCr15 steel ball were studied on the friction and wear tester,and the wear mechanism of 7055 aluminum alloy was discussed by analyzing the wear surface morphology with scanning electron microscope.It is found that the specimen obtained by the twostage solidification treatment (240 ℃×2 h+480 ℃×2 h) shows the best performances,such as the highest hardness,lower surface roughness and the lowest friction coefficient,while the specimen obtained by the high temperature preprecipitation (480 ℃×2 h +240 ℃×2 h) shows the worst performances.The higher the hardness of the sample after solution treatment,the lower the friction coefficient,and the surface roughness and friction coefficient shows a nonlinear relationship.The lowest friction coefficient can be obtained when the surface roughness of the specimen between 0.35 and 0.5 μm.When the surface roughness of 7055 aluminum alloy is high,adhesive wear,abrasive wear and surface fatigue wear mainly occur during dry friction,when the surface roughness is low,adhesive wear and fatigue wear mainly occur.