Abstract: Aiming at the problem of CO₂ corrosion of X100 steel in the crude oil environment, the effects of moisture content, temperature, partial pressure of CO₂ and flow rate on the corrosion behavior were studied by experiments, which can lay a foundation for the safe use of X100 pipelines. The results show that as the water content of crude oil increases, the corrosion rate of X100 steel gradually increases; as the temperature increases, the corrosion rate increases and then decreases.At 40 ℃, the corrosion product film on the surface of the steel plate is relatively loose, then, the corrosion is the most serious;with the increase of CO₂ partial pressure in crude oil, X100 steel shows a trend of first increase and then decrease. When CO₂ partial pressure in crude oil is 2.5 MPa, there are multiple layers of corrosion products. With the gradual increase of the flow rate of crude oil, the corrosion rate of the steel materials increases first and then decreases. At the velocity of 1.0 m/s, the corrosion of steel materials is relatively serious. There are many small and deep holes on the steel surface.