The microstructure characteristic and wear behavior of the severe deformation surface constitution of Ti-4Al-2V alloy were studied in this paper. The results show that the wear resistance of the deformed surface is much better than that of the coarse grain surface. And the wear mechanism of the nanocrystalline surface is different from that of the coarse grain surface. The former is particle wear mechanism of harder material and the latter is adherence wear mechanism. The influence factors on the wear resistance of the nanocrystalline surface have been discussed.