Abstract: To investigate the influence of different laser shock peening (LSP) process parameters on the microstructural evolution and mechanical properties of titanium alloy, the peening process was simulated to screen three representative sets of LSP process parameters using explicit dynamic and implicit static finite element methods. On this basis, experimental measurements were conducted to analyze the variations in rotational bending fatigue life, residual stress, and microstructure of the titanium alloys before and after LSP impact strengthening. The results demonstrate that TC6 titanium alloy exhibits optimal performance after treatment with a laser power density of 7.63 GW/cm² and a spot overlap rate of 50%. Notably, the rotational bending fatigue life of the surface-strengthened TC6 titanium alloy is enhanced by over 400%, while the maximum value of the material surface prefabrication of residual compressive stress is 744 MPa. Concurrently, the fracture morphology has a distinct change, characterized by decreased the fatigue stripe spacing, which manifests the significant improvement in surface integrity and effective suppression of fatigue crack extension. The cross-section organization shows grain refinement, accompanied by a large number of substructures, and the content of subgranular boundaries is increased to 22.5%~33.9%, which provides an important basis for the application of LSP in aero-engine components.