Objective in order to improve the understanding of CO2 corrosion machine at different temperature in multiphase flow state. Methods the CO2 corrosion state of X70 steel under the condition of plug flow was simulated by using the self-made experimental device and the hanging plate experiment. The surface morphology, corrosion rate and online coupon corrosion situation were observed and analyzed by electron microscopy and electrochemical monitoring. The effect of temperature on the CO2 corrosion rate of X70 steel was focused on. Results the CO2 partial pressure has little effect on the corrosion rate, and the corrosion rate decreased to a lower level when temperature reaches 90-98℃, due to the influence of corrosion product film; when temperature is between 60-80℃, the corrosion state of the hanging plate surface is not stable, and partial corrosion or uniform corrosion occurs, which depends on the CO2 partial pressure. When the CO2 partial pressure is low, such as 0.15MPa, it is easy to form uniform corrosion, and when the CO2 partial pressure is high, such as 0.6MPa, it is easy to form partial corrosion. when temperature is between 40℃-80℃, the temperature is higher and higher at the highest point of the corrosion rate with the increasing of CO2 partial pressure, and the temperature range generally remains between 40℃-80℃at the highest point of the corrosion rate. Conclusion the effect of temperature on the CO2 corrosion of X70 steel is closely related to the partial pressure of CO2. At the same temperature, the corrosion rate increases with the increase of CO2 partial pressure, and the temperature of the corresponding maximum corrosion rate is becoming higher and higher. It is not accurate that CO2 corrosion rate peaked the highest under a certain temperature isolated.