Abstract: In order to clarify the cause of corrosion and scale formation in oilfield water injection pipeline, the water quality and scale samples were analyzed by X-ray diffractometer and atomic absorption spectrophotometer, and the corrosion rates under the combination of different temperatures, CO₂ content, H₂S content and SRB bacteria content were measured by electrochemical testing technology. Orthogonal experiments were designed to study the main controlling factors of corrosion damage under multi-factor coupling. The results showed that corrosion scale was dominant in the scale sample components. The temperature was the main control factor of corrosion scale formation, and both CO₂ and H₂S have dual effects on corrosion.