When the pressure of CO2 is 2 MPa, through the autoclave corrosion tests of annealed N80 steel specimens in simulated oil field water solution at different temperature, the mechanism of corrosion and the change rule of corrosion resistance with the change of temperature were discussed. In the autoclave tests, some iron elements of the specimens become Fe2+ ions and the Fe2+ ions go into the solution, which results in the corrosion weight loss. Scaling develops because the CO32- ions in the simulated oil field water solution react with iron elements of the specimen. To QPQ treated specimens, with the increase of temperature, the compactness of the scaling increase, the corrosion weight loss and the weight of scaling decrease. In the same temperature, the corrosion weight loss and the weight of scaling of QPQ treated specimens are both lower than that of untreated specimens.