Objective The surface of commercial X80 pipeline steel was modified using plasma nitriding, to study the corrosion resistance and rule of plasma nitriding X80 steel immersed in Ku’erle soil simulation solution for 30 days, 60 days, and 90 days. Methods The effect of the nitrided layer on the corrosion resistance of X80 steel was investigated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) measurement, The morphology and composition of the corrosion products were investigated using SEM, XRD, and EDS. Results The results showed that: with the increasing corrosion time, the corrosion current density of nitrided X80 steel decreased to 1. 33 μA/ cm2, the corrosion potential increased to -225 mV, and the corrosion rate was significantly reduced; the corrosion products were mainly composed of Fe2O3, FeO (OH), Fe(OH)3 and Fe3O4. Conclusion As compared with the X80 steel, after immersion for the same time, the specimen treated by plasma nitriding had a more positive corrosion potential, the corrosion current density was decreased by one order of magnitude, the charge transfer resistance was increased by two orders of magnitude, and the corrosion resistance was higher.