Abstract: Pipeline transportation is one of the most economical and efficient ways of CO₂ transportation in carbon capture, utilization and stgorage (CCUS) technology chain. Corrosion simulation tests on gas-phase CO₂ transportation pipelines under conditions containing trace amounts of water and oxygen impurities was conducted in deep water multiphase flow dynamic corrosion evaluation system. The results indicate that the presence of trace amounts of water in gas-phase CO₂ transportation pipelines could cause severe corrosion, and the addition of trace amounts of oxygen could exacerbate the corrosion. Therefore, for gas-phase CO₂ transmission pipelines, the water and oxygen content in the fluid should be strictly limited to control the internal corrosion of carbon steel transmission pipelines.