In this study, the LSP surface treatment of a Ti80 alloy is implemented, and the corresponding microstructural evolution and properties are investigated systematically. After LSP, the surface grains of the Ti80 alloy are significantly refined, and many defects such as dislocation tangles, stacking faults, and deformation twins are formed. The strengthening effect of crystal defects combined with fine grain strengthening increase the surface microhardness by 21.7%. However, the large compressive residual stress is formed, resulting in enhanced strength and elongation, and the overall mechanical properties of the Ti80 alloy become better. Grain refinement provides more nucleation sites for the formation of passivation film of the Ti80 alloy, while the compressive residual stress makes the passivation film denser and less susceptible to destruction, resulting in a positive shift of the corrosion potential of the Ti80 alloy in the 5 mol/L HCL solution by 119 mV. The corrosion current density is reduced by 0.52 μA·cm^-2 and the corrosion rate is reduced by 0.16 mm·a^-1, therefore the anticorrosion property is improved.