Abstract: The corrosion and fatigue resistance of pressure vessel material Q345R steel after laser shock peening was studied. By electrochemical experiment and SEM micro-analysis, it shows that the corrosion resistance of the samples treated by LSP (Laser Shock Peening) with absorber layer and without absorber layer is increased by 5.8 times and 2.6 times respectively. The micro-experiment results show that the surface crack of corroded sample after LSP treatment is significantly less than untreated specimen. While the corrosion resistance decreases with the increase of the number of LSP. The S-N curves obtained from fatigue tests show that under the same stress conditions, the fatigue life after 1 hour and 2 hours’ corrosion is reduced by 36.8% and 56.4% compared to the original sample and the fatigue life after one and three LSP treatments times is increased by 43.8% and 198.2%. After XRD inspection tests, it is found that the laser shock peening can form a certain depth of residual compressive stress layer on the surface and effectively inhibit fatigue crack expansion.