The oil well pipe will be affected by mechanical factors, environmental factors and media factors at the same time during its service.Taking P110 steel as an example, in order to explore the influence of multi-factor coexistence conditions on CO2corrosion of P110 steel,the electrochemical behavior of P110 steel based on the condition of coexistence of "Compressive Stress-Temperature-NaCl" in saturated CO2environment was investigated by orthogonal test and electrochemical measurement methods.The results show that the effect of temperature on the electrochemical behavior of P110 steel is most significant in the condition of coexistence of "Compressive Stress-Temperature-NaCl",and the electrochemical reaction rate of CO2corrosion process of P110 steel increases with the rise of temperature.The effect of NaCl and compressive stress on electrochemical behavior of P110 steel is far less than that of temperature,but the influence degree of them is close.With the increase of NaCl content, the electrochemical reaction rate of CO2corrosion process of P110 steel increases first and then decreases,and the critical NaCl content at the inflection point is 3.5%.With the increase of compressive stress, the electrochemical reaction rate of CO2corrosion process of P110 steel also increases first and then decreases,and the critical compressive stress at the inflection point is 90%σs.Therefore, more attention should be paid to the failure risk caused by CO2corrosion at high temperature for P110 steel serving in the conditions of coexistence of "Compressive Stress-Temperature-NaCl".