Abstract: The filtration and separation equipments are the key equipments of natural gas purification plant for sour gas field, the corrosion failure of the equipments reveives much concern. Field survey results showed that the corrosion layer appeared at the fluid position of the bottom of equipments after a period of time, and there were more bubbles at the separation device. The failure factors were ensured by metallographic analysis, physical and chemical properties analysis and corrosion microscopic analysis, and then the main corrosion control factors were founded by laboratory simulation of field. The results showed that under the premise of the material mechanical properties and chemical composition meeting the requirements of the standard, the main factor for equipment failure of bubbling was impurities in the materials. As the H₂S and CO₂ partial pressure ratio increasing, the corrosion rate increased, and the hydrogen bubble phenomenon became more serious.