Corrosion control is an important issue in the process of oil and gas pipeline transportation. CO2 is the most common corrosion medium in oil and gas pipelines. It is of great scientific significance and economic value to study the corrosion mechanism and protective measures of CO2. The corrosion mechanism of CO2 is reviewed, including chemical reaction, electrochemical reaction and mass transfer process. The existing corrosion theories are discussed in depth, and it is found that the cathodic reaction has an important effect on CO2 corrosion, while the effect of CO2 on the anodic process is not clear. On the basis of the corrosion mechanism, in view of the actual working conditions of the pipeline, combined with the electrochemical experimental results, the influence of various factors on the corrosion behavior of CO2 is expounded. Combined with the influencing factors of CO2 corrosion, the defects of common pipeline protection measures are discussed:the cathodic protection system is greatly affected by potential, so a new cathodic protection potential should be established to ensure the cathodic protection effect under the action of stray current. Coating protection is easy to degrade and lose protection under the interference of stray current. Most corrosion inhibitors are harmful to environment. Finally, the development direction of CO2 corrosion and protection in the future is prospected:in order to further understand the corrosion mechanism of CO2, systematic experimental tests on the electrochemical corrosion behavior of CO2 are needed. It is also one of the future research directions to study the synergistic effect of different corrosion inhibitors, the use of environment-friendly green corrosion inhibitors, the use of new materials to develop intelligent coatings and new cathodic protection systems.