The surface integrity and fatigue life of Ti-17 rotary bending fatigue specimens after ultrasonic rolling strengthening were investigated. The results show that the fatigue crack initiation position of the ultrasonic rolling specimen is located on the subsurface of the specimen, and the crack initiation is related to the stress concentration caused by the internal defects of the material and the uneven distribution of residual stress. The improvement of ultrasonic rolling on the rotary bending fatigue performance of Ti-17 is mainly reflected in the delay of crack initiation. The crack initiation life of the three groups of samples reaches more than 97% of their total life. After ultrasonic rolling, the surface roughness of Ti-17 samples is low, the Ra value is mostly within 0.2 μm, and the surface stress concentration coefficient is low, which reduces the possibility of crack initiation from the surface. The introduction of a deeper residual compressive stress layer and a work hardening layer hinders the nucleation of fatigue cracks and reduces the crack nucleation rate. The surface grains are significantly refined, and the high density of the dislocation wall can significantly improve the fatigue strength of the material.