In this study, FeCrMnxAlCu (x = 0, 0.5, 1.0, 1.5, 2.0) high-entropy alloys were prepared using a vacuum arc melting furnace. The microstructure and chemical composition of the alloys were analyzed using equipment such as XRD, SEM, and EDS. Additionally, the corrosion resistance of the alloys in 3.5 wt.% NaCl solution was evaluated through electrochemical polarization curve tests and immersion experiments. After corrosion, the alloy surfaces were analyzed using XPS equipment.The results of microstructure characterization showed that the prepared high-entropy alloys exhibited typical dendritic and interdendritic structures and possessed a dual-phase structure of FCC and BCC . Corrosion test results indicated that the corrosion resistance of the high-entropy alloys increased initially and then decreased with an increase in Mn content. However, compared to the alloy without Mn, alloys containing Mn still exhibited better corrosion resistance. Among them, the FeCrMnAlCu high-entropy alloy demonstrated the best corrosion resistance, with a more positive corrosion potential (Ecorr = -0.417 V) and a smaller corrosion current density (Icorr = 2.120×10-6 A?cm-2). Furthermore, the FeCrMnxAlCu high-entropy alloys activated and formed discontinuous and loose corrosion product films.