The work aims to study the effect of temperature on corrosion of J55 carbon steel in CO2/brine environment and the description method of corrosion morphology. CO2/brine corrosion environment at 9 MPa and different temperature was simulated by autoclave and the average corrosion rate of J55 carbon steel was determined respectively at 50 ℃, 65 ℃ and 80 ℃. Corroded coupons surface was scanned, extracted and analyzed by the full-automatic 3-D microscopic imaging system and the characteristics of corrosion morphology were characterized at different temperature. At the same time, J55 carbon steel corrosion test in CO2/brine environment was conducted at different temperature and pressure in order to verify the distribution of corrosion morphology. With the increase of temperature, the average corrosion rate of CO2/brine to J55 carbon steel decreased first and then increased and the average corrosion rate was 2.1871 mm/a at 65 ℃. The surface corrosion morphology of the coupon was collected in 9-threshold splicing with magnification times of 200 and contact ratio of 10% in the bright field. Extracted image area accounted for 12.28% of the whole coupon. The surface corrosion depth distribution of coupon accorded with the Gauss distribution. The correlation coefficient was 0.9790. The change trend of xc and average corrosion rate was consistent with temperature. The parameter w could reflect the type of corrosion morphology. The same conclusion was obtained from the corrosion test of J55 carbon steel at different temperature and pressure in CO2/brine environment. With the increase of temperature, the corrosion morphology of CO2/brine environment on J55 steel gradually transforms to uniform corrosion from pitting corrosion. The surface corrosion depth distribution of coupon accords with Gauss distribution and the parameters can reflect the corrosion behavior of CO2/brine water on J55 carbon steel. The corrosion morphology description method can effectively avoid subjectivity and the randomness in the description of morphology.