Since CO2corrosion has become a serious problem in most oil pipelines in Xujiahe formation of western Sichuan, Company launches corresponding researches and carries out a serious of measures, such as replacing with anti-corrosioncoated tubing, injecting anti-corrosion inhibiter, and drawing up tubing replacing scheme which are based on the simulated corrosion rate experiment. All these achieve good results. However, since anti-corrosion measures in some tubing hasn’t meet the expectation, this paper, based on the coupling model, focuses on the CO2corrosion and its impact factors under the condition of fluid flowing state. Analysis with on-site production data shows that temperature affects corrosion rate by altering chemical activity, pH changes corrosion rate by affecting H+concentration, and flow rate alters corrosion rate by affecting substance transmission speed. Besides, corrosion in tubing of different positions has their own dominant factors. It suggested to target on the dominant corrosion factors and adopt corresponding measures.