In order to solve the urea corrosion problem of N80 steel oil casing string used in urea assisted heavy oil steam huff and puff environment in oilfield, the urea corrosion experiment was carried out by high temperature and high pressure dynamic corrosion kettle experiment system to simulate the wellbore working environment of urea assisted steam huff and puff production wells. Before the experiment, 1 L of urea solution of different concentrations was predeoxygenated by N2 at room temperature for 4 h. A set of 3 pieces of 50 mm×10 mm×3 mm hanging sheet samples processed from N80 steel was put into the high temperature autoclave, and the pre-deoxygenated solution and crude oil were imported into the kettle. The deoxygenation continued for 2 h before all valves were closed. The stirring speed was set to 1 000 r/min to start the experiment. During the experiment, the kettle was heated up as it was stirred, and the temperature was heated up to 150 ℃ to keep warm until the pressure gauge reading did not change. After the urea in the solution was completely decomposed, the temperature was then reduced to the experimental temperature (50 ℃ and 80 ℃). When the temperature reached the experimental temperature, the experimental time was recorded, and the experimental period was 240 h.