Abstract: Using methods of corrosion coupon in high temperature and high pressure, chemistry analysis of gas water and multi-arm caliper logging tool, the application effects of corrosion inhibitor were studied on H₂S/CO₂ gas well. Test resuilts showed that the selected corrosion inhibitor has good effect of anti-corrosion, after addition of corrosion inhibitor for 4 years, the corrosion rate of full tubing was 0.04 mm/a, lower than 0.1 mm/a corrosion control standard; the corrosion areas were mainly concentrated at the top and bottom of the tubing.