High Energy Shot Peening (HESP) was used to treat the material surface in order to study the effects of surface nano-crystallization of 7055 aluminum alloy on wear behavior. The nano-crystalline layer was obtained on sample surface. TEM was used to analyze the microstructure before and after nano-crystallization, meanwhile, residual stress and micro-hardness were measured on surface, and wear behaviors of nano-crystalline surface were examined by reciprocating wear tester as well. The experiment results show that, HESP caused severe plastic deformation on surface, and there exits compressive residual stress with large magnitude on surface, and the maximum value is -369MPa, meanwhile, the compressive residual stress layer come up to 0.6mm.The micro-hardness increases by 50% compared to matrix. The frictional wear experiments show that, HESP nano-crystallization can apparently decrease friction factor, and the wear loss is only 32% of untreated samples, HESP largely improved the wear-resisting property of 7055 aluminum alloy.