The work aims to study corrosion inhibition effects of four novel ionic liquids on N80 steel. The corrosion inhibition rate of the ionic liquids was compared by virtue of static weight-loss and dynamic weight-loss methods. The N80 carbon steel was characterized by electrochemical test, scanning electron microscope and EDS to evaluate corrosion inhibition of the products. The protective film, which was mainly composed of iron, carbon and oxygen elements, took shape on the surface of the iron sample after composite ionic liquids were added to the oilfield produced water. The corrosion rate decreased slowly as 150 mg/L of 4 corrosion inhibitors was added. The inhibition efficiency of type B corrosion inhibitor was the best of all. When 150 mg/L was consumed, the corrosion rate decreased to 0.0087 mm/a; the self-corrosion potential increased from 0.8112 V to 0.7446 V; the self-corrosion current decreased from 77.79 μA to 5.03 μA; and the inhibition rate amounted to 93.5%. The 4 ionic liquid corrosion inhibitors provide favorable inhibiting effects for N80 steel in oilfield produced water with inhibition efficiency as B>C>D>A. The inhibition performance of B is the best and can be up to 94.1% when measured by virtue of weight loss method.