In this paper, the effect of Cr element on the phase composition, microstructure, phase evolution of FeNiCuCoCrx(x=0, 0.5, 1.0, 1.5, 2.0) high-entropy alloy powders and on the high-temperature oxidation resistance and corrosion resistance of bulk high-entropy alloys were systematically investigated. The results show that the high-entropy alloy powders after mechanical alloying are composed of face-centered cubic (FCC) phase and body-centered cubic (BCC) phase. With the increase of Cr content, the strength of the characteristic peak of BCC phase increases. The BCC phase of FeNiCuCoCrx(x=0, 0.5, 1.0, 1.5, 2.0) high-entropy alloys is dissolved in the matrix during high-temperature sintering, and the FCC phase is decomposed into Cu-rich phase (FCC1 phase) and Cu-deficient phase (FCC2 phase)， and the microstructure and composition uniformity of the alloy is high. During the isothermal oxidation process at 900 ℃, the FeNiCuCoCr0.5 high-entropy alloy forms a continuous and dense oxide film that adheres tightly to the substrate. When the thickness of the film is 25 μm, its high-temperature oxidation resistance is the best. The electrochemical tests results in 3.5% (mass fraction) NaCl solution reveal that the FeNiCuCoCr0.5 high-entropy alloy exhibits the best corrosion resistance, with a corrosion current density of 5.56×10-8 A/cm2 and a charge transfer resistance of 6 821 Ω·cm2. Compared to other FeNiCuCoCrx(x=0, 1.0, 1.5, 2.0) high-entropy alloys, the corrosion current density is one order of magnitude lower. Compared to other FeNiCuCoCrx(x=0, 1.0, 1.5, 2.0) high entropy alloys, the transfer resistance of FeNiCuCoCr0.5 high entropy alloy increases by 51.9%, 18.8%, 233.4% and 265.3%. The research results provide new ideas for the composition design of corrosion-resistant FeNiCuCoCr high-entropy alloys.