TC4 titanium alloy was employed to investigate the effect of shot-peening coverage(SPC) on surface integrity, such as surface morphology, surface roughness, residual stress and microstructure after 200°C/1h heat treatment. The results show that the average roughness Ra, root-mean-square roughness Rq and the value of compressive residual stress increase with the rise of SPC. Dislocation movement and crystal self-coordinating are observed in 300% SPC after 200°C/1h heat treatment due to temperature and inner-stress, which causes the relaxation of residual stress, and more over, the relaxation is not observed in 100% SPC after 200°C/1h heat treatment.