Abstract: Static corrosion immersion loss tests were conducted on P110SS at different temperatures and pressures using a high-temperature and high-pressure reactor. The morphology and composition characteristics of the corrosion products were characterized by analysis methods such as SEM and EDS. The results indicat that regardless of whether CO₂ was in a dense or supercritical state, the effect of temperature on the corrosion rate of P110SS showed a trend of first increasing and then decreasing. The corrosion rate was highest at 80 ℃, gradually decreasing with increasing temperature, and remains stable above 180 ℃. As the CO₂ pressure increased, the corrosion rate gradually increased. After CO₂ entered the supercritical state, the trend of corrosion rate increasing with pressure weakened. The corrosion rate of P110SS at different temperatures was mainly related to the precipitation kinetics of corrosion products. At the same temperature, the trend of the corrosion rate of P110SS showed a similar correspondence with the solubility of CO₂ in water.