Abstract: Aiming at the severe high-temperature corrosion and erosion wear problems on the surface of the water wall in thermal power boilers, high-speed laser cladding technology was used to prepare dense NiCrAlY alloy coating without cracks on the surface of 15 CrMo water wall pipes. SEM, EDS, EBSD, XRD and other characterization methods were used to characterize the microstructure and mechanical properties of the coating, and then the high temperature corrosion resistance and impact wear properties of the coating were tested in the simulated service environment. The results show that the NiCrAlY coating is mainly composed of γ-Ni, AlNi₃ and tiny Al₂Y₄O₉ and Al₅Y₃O₁₂. γ-Ni grains show orientation characteristics in some degree, and gradually change from the planar to equiaxed grains along the deposition direction. The rest phases mainly precipitate inside the grain and along the boundaries. The hardness of the high-speed laser cladding NiCrAlY coating is about 330.61 HV, which is significantly higher than that of 15CrMo substrate. At 600 ℃, the high-temperature corrosion weight gain of NiCrAlY coating after 192 h is about 90.5% lower than that of the substrate,and the high-temperature erosion volume loss is about 60.1% lower. The high-speed laser cladding coating has excellent resistance to high-temperature flue gas/molten salt coupled corrosion and high-temperature solid particle erosion wear, which is potential in the application of protective coating on the surface of boiler water wall.