Abstract: Referring to the idea of orthogonal test, the effect of "tensile stress-temperature-Cl^- concentration" coexistence system on electrochemical behavior of P110 steel in CO₂ environment was investigated using electrochemical measurement. The results show that in saturated CO₂ environment, the influence order of factors in the coexisting system on the electrochemical behavior of P110 steel was as follows:temperature > Cl^- concentration > tensile stress. The electrochemical reaction rate of P110 steel would be increased by increasing temperature, Cl^- concentration and tensile stress (below yield strength) in the coexistence system, which would promote the CO₂ corrosion reaction of P110 steel.