This paper aims to study the effect of dry shot peening and wet shot peening on the residual stress field of TC17 titanium alloy. The surface of TC17 titanium alloys was successively strengthened by dry and wet shot peening of different strengths. Using X-ray diffractometer, EBSD and hardness tester, the author analyzed the effect of the two processes on the residual stress field, microstructure and hardness field of titanium alloy. When the shot peening strength was 0.20 mmN, the maximum residual stress introduced by dry shot peening in TC17 titanium alloy was 30 μm from the surface, while the maximum residual stress introduced by wet shot peening in TC17 titanium alloy was on the surface. When the shot peening strength was 0.30 mmN, the depth of the residual stress field induced by dry and wet shot peening was respectively 200 μm and 90 μm. The residual stress introduced by dry shot peening was deeper than that of wet shot peening. When the shot peening strength was 0.40 mmN, the maximum residual stress of dry shot peening was -1191.5 MPa, while the maximum residual stress of wet shot peening was -943.9 MPa. The maximum residual stress introduced by dry shot peening was greater than that of wet shot peening. When the shot peening strength was increased to 0.50 mmN, both dry and wet shot peening processes had experienced overshot peening. The residual stress near the surface layer relaxed and the hardness value decreased. Through EBSD research, it was found that as the shot peening strength increased, the low-angle grain boundary ratio of α phase in the surface layer of TC17 titanium alloy increased first and then decreased. When the shot peening strength was 0.50 mmN, the proportion of low-angle grain boundaries in α phase decreased, and the proportion of high-angle grain boundaries increased. Results indicate that when the shot peening strength is low, the maximum residual stress introduced by dry shot peening is on the subsurface, while that introduced by wet shot peening is on the surface. When the shot peening strength is high, both the dry and wet shot peening processes have experienced overshot peening. At this time, a large number of low-angle boundaries are transformed into high-angle boundaries, the hardness field of the titanium alloy surface layer is reduced, and the residual stress field undergoes stress relaxation.