Tahe oilfield has a condition of high temperature，high oxygen and high salinity. The corrosion phenomenon of water injection pipeline and water injection well is serious. In order to effectively alleviate the serious corrosion situation of Tahe oilfield， Mannich base was synthesized by using acetic acid，benzylamine and acetophenone as raw materials，and then mixing it with surfactant（fatty alcohol polyoxyethylene ether，fatty alcohol polyoxyethylene ether phosphate），etc. to prepare Mannich base corrosion inhibitor. On the condition of high temperature and high pressure，the effect of dissolved oxygen and oxygen content on the corrosion of steel was investigated. The performance of inhibitor was evaluated by weight loss method and electrochemical test method. The results showed that the dissolved oxygen could increase the corrosion of pipeline. The corrosion rate increased with increasing oxygen concentration. The amino group and benzene ring in the Mannich base corrosion inhibitor formed an electron-rich conjugated system，which had a strong adsorption capacity. The inhibition rate could reach 92.57%，and the corrosion inhibition performance was good. Mannich base corrosion inhibitor was a mixed inhibition type corrosion inhibitor mainly for inhibiting anode reaction，which could effectively inhibit the corrosion under high temperature and high oxygen conditions.