Abstract: The sucker rod of a sulfur-containing oil well in northern Shaanxi is seriously corroded, and it will break after service for about 1 year. The macroscopic morphology of the fractured sucker rod was analyzed, and the corrosion characteristics were analyzed by SEM, EDS and XRD. The failure reason of the sucker rod was determined by combining the service conditions of the sucker rod. At the same time, the sucker rod material suitable for the oil well was optimized by on-site corrosion rate detection, corrosion product film characterization and tensile performance test. The results show that the chemical composition of the failed 3130 alloy steel sucker rod meets the standard, there are a large number of corrosion pits on the surface of the sucker rod. The average corrosion rate is about 1.6986 mm/a, and the maximum pitting depth is 3.5 mm. The corrosion products are mainly FeCO₃, Fe₇S₈ and CaCO₃. The main reason for the fracture of the sucker rod is CO₂/H₂S corrosion caused by high salinity sulfur-containing produced water. High Cl^- content will also promote the development of pitting corrosion. The corrosion resistance of the three sucker rod materials is 4330A alloy steel>25CrMoA alloy steel> 3130 alloy steel. After 187 days of corrosion, the surface of 4330A alloy steel and 25CrMoA alloy steel is flat, and the tensile performance can reach the D-class sucker rod standard. It is recommended to use 4330A alloy steel sucker rod with good corrosion resistance on site.