The EOR technology of CO₂ flooding is increasingly used because of its advantages, but it is also accompanied by the high risk of corrosion and scaling in the surface production and transportation system. As a result, this study was carried out using the electrochemical test method and the static scale inhibition method to evaluate and select corrosion and scale inhibitors commonly found in oil field. After the compatibility and synergy test of the corrosion and scale inhibitor, the most effective compound inhibitor was prepared. Finally, the comprehensive protection performance of the compound inhibitor was evaluated by weight loss method and scale inhibition rate test under simulated condition. The experimental results showed that: the corrosion inhibition rate of the selected corrosion inhibitor and scale inhibitor in the simulated formation water of saturated CO₂ at 55 ℃ and atmospheric pressure is 93.06% and scale inhibition rate is 95.18% for the typical 20 steel used in the production and transportation system. After mixing together the selected corrosion inhibitor and scale inhibitor, the corrosion rate of the 20 steel is controlled within 0.045 mm/a when the amount of the composite corrosion and scale inhibitor is injected at 500 mg/L under the simulated condition. The scale inhibition rate is 93.91%, which can meet the performance indicators of oil field. The results showed that the compound corrosion and scale inhibitor can play a good role in protecting the production and transportation system of CO₂ flooding facilities, and guarantee the safe operation and production activities.