Abstract: In order to improve the problems of contact wear and fatigue fracture of β-type titanium alloy TB11（Ti15Mo）in medical treatment, it is necessary to strengthen the surface properties of the alloy. The controlled variable method was used to mechanically hammer the surface of TB11 alloy, and the nanostructures with different grain sizes were successfully prepared on the surface of the alloy. At the same time, the relationship between surface grain size and hardness and wear resistance was studied. The results show that after hammering for 30 min, the surface grain size of TB11 titanium alloy is basically stable, the size is 32.21nm, and the hardness increases from 288 HB to 399 HB, with an increase of about 42.5%,and the smaller the grain size, the greater the hardness. Combining the wear morphology and pin-disk wear finite element simulation results, using Archard wear model to calculate, after the grain size is reduced to 30.84 nm, the wear depth reduces by about 30% compared with the original grain. The smaller the surface grain size of TB11 alloy, the stronger the wear resistance, and the less easily the nano-layer is worn, which indicate that the mechanical hammering can effectively improve the surface properties of TB11 titanium alloy.