With the gradual increase of oilfield production costs, the corrosion resistance of oil pipelines has received more and more attention. In order to obtain oil pipelines with excellent corrosion resistance, based on the Fe-25Mn-3Si-3Al TWIP steel, Cr and Mo were added, Mn content was reduced to design and produce Fe-20Mn-7Cr-0.9Mo steel. According to the difference of oilfield environment in China, this paper focused on the corrosion behavior of Fe-20Mn-7Cr-0.9Mo steel in three oilfield produced water simulation liquids, and provide theoretical guidance for its application in oil pipelines. Firstly, the microstructure of Fe-20Mn-7Cr-0.9Mo steel was analyzed by XRD and TEM. Then, the polarization curve and EIS of Fe-20Mn-7Cr-0.9Mo steel were investigated in three oilfield produced water simulation liquids by Electrochemical Workstation. The scanning range of the polarization curve was ?1.15 V to ?0.3 V, and the scanning rate was 0.001 V/s. The EIS measurements were performed at open circuit potential and the spectra were acquired in the frequency range 10?2 Hz to 105 Hz with an amplitude of 10 mV. The corrosion products were analyzed by SEM after the electrochemical test. Meanwhile, the corrosion behavior of Fe-25Mn-3Si-3Al TWIP steel in the same environment was used as a control experiment. The results showed that the microstructure of Fe-20Mn-7Cr-0.9Mo steel was dominated by austenite, and the grains contained a large number of stacking faults, annealing twins and martensite with a high-density dislocation structure. The addition of Cr and Mo, and the reduction of Mn content reduced the stacking fault energy of Fe-20Mn-7Cr-0.9Mo steel, resulting in the formation of a large number of stacking faults, annealing twins and a small amount of martensite in the grains. The polarization curves analysis showed that compared with Fe-25Mn-3Si-3Al TWIP steel, Fe-20Mn-7Cr-0.9Mo steel was passivated in three oilfield produced water simulation liquids, the corrosion potential was increased, and the corrosion current density was significantly reduced, which were 1.7, 0.08 and 2.1 μA/cm2. The EIS analysis showed that Fe-20Mn-7Cr-0.9Mo steel revealed a single capacitive loop in three oilfield produced water simulation liquids, and the polarization resistance (Rp) values were 3 111, 5 322 and 3 582 Ω.cm2, respectively, while Fe-25Mn-3Si-3Al TWIP steel revealed a capacitive loop and an inductive loop in three oilfield produced water simulation liquids, and the corresponding polarization resistance (Rp) values were only 530, 273 and 528 Ω.cm2, much smaller than those of Fe-20Mn-7Cr-0.9Mo steel. In three oilfield produced water simulation liquids, a large amount of corrosion products existed on the surface of Fe-25Mn-3Si-3Al TWIP steel, and a corrosion product film was formed, while only a few corrosion products existed on the surface of Fe-20Mn-7Cr-0.9Mo steel. The addition of Mo and Cr, the reduction of Mn content and the formation of a large number of annealing twins in the grains effectively reduced the corrosion reaction rate, and improved the corrosion resistance of Fe-20Mn-7Cr-0.9Mo steel in three oilfield produced water simulation liquids.