To improve the high-temperature oxidation characteristics of the Al₂O₃/CoNiCrAlY coatings, they are prepared on the surface of the K438 alloy via laser cladding. In addition, the effects of different energy densities on the microstructure and high-temperature oxidation behavior of materials are studied. The experimental results indicate that the Al₂O₃/CoNiCrAlY coatings comprise α-Co, γ-Ni/Cr, Al₂O₃, Ni₃Al, and Ni₂Cr₃. The coating will exhibit an appropriate microstructure after the addition of Al₂O₃. Further, the coating is oxidized at 1100 ℃ to obtain AlN at the grain boundary. The oxide films form on the coating surface comprise an inner layer of α-Al₂O₃ oxide and an outer layer of Cr₂O₃ and (Co,Ni)(Al,Cr)₂O₄ mixed oxide. All the kinetic curves of the high-temperature oxidation of the coating under different energy densities conform to the parabolic law. The coating exhibits optimal high-temperature oxidation resistance when the energy density is 64.97 J/mm ³.