Fretting fatigue frequently causes the failure of critical components in aerospace and aviation. This study investigates fretting fatigue in the dovetail slots structure of Ti-6Al-4V titanium alloy. Surface strengthening method was developed as Deflected Abrasive Waterjet Process (DAWJP). Experimental research was conducted at both room and high temperatures. FRANC3D and finite element simulations were used to investigate the effects of initial crack angles, crack depths, axial loads, and residual stresses on crack propagation. Crack propagation was analyzed using DIC techniques, and then fracture morphology was examined through SEM. Additionally, a full-life prediction model was proposed incorporate the crack propagation life and temperature effects. The results indicate that the crack propagation in dovetail slots is primarily dominated by mode I cracks, and the initial crack angle has minimal impact on crack initiation life. The crack propagation direction ultimately aligns perpendicularly to the contact surface. DAWJP reinforcement significantly improves the dovetail slots specimen fretting fatigue life, and then reduces the number of crack sources and fatigue striation spacing. Additionally, the higher loads result in smaller fatigue striation spacing. The error between the model's predicted life and the actual life is controlled within two times of the acceptable error range.