Seven FeCrAlY-Al₂O₃ nanoceramic composite coatings are deposited on F/M steel via plasma spraying and laser remelting. A systematic investigation is conducted to examine the dependence of microstructure, mechanical properties, and lead–bismuth eutectic (LBE) corrosion resistance on the nano-Al₂O₃ addition and different Cr and Al contents. With the increase in Al content in FeCrAlY, gradual refinement of the coating grains occurs. The addition of nano-Al₂O₃ promotes the elemental segregation and precipitation of the second phase. The nano-Al₂O₃ notably enhances the mechanical properties of the coatings that are primarily attributed to second-phase and fine-grain strengthening. After LBE corrosion tests, intergranular corrosion morphology could be observed, where the contents of Cr and Al significantly influence the corrosion behavior of the coatings at varying temperatures.