In order to study the influence of laser shock peening on residual stress distribution and fatigue properties of TC4-DT titanium alloy rod,the distribution of residual stress in the smallest diameter cross section of the rod under different impact loads was analyzed by using ABAQUS finite element software.Then the samples were subjected to laser shock test and tensile-pull fatigue test,and the fatigue fracture morphology was compared and analyzed.The results show that rods can produce residual compressive stress layer in the surface and near-surface,and the tensile stress is produced in the inner and central regions.Because the area of the internal tensile stress is much larger than the area of the surface compressive stress,the fatigue crack growth is accelerated and the fatigue life is reduced,which adversely affect the tensile fatigue properties of the rod specimen.After laser shocking,the fatigue crack source is transferred to the inside and located in the region which produced maximum tensile stress.This study has a certain reference value for the application conditions of shaft parts after laser shock peening.