Corrosion of the molten salts Na 2SO 4 and NaCl has become one of the major factors in the failure of steel components in boilers and engines. In this study, CoNiCrAlY cobalt-based cladding layers with different NiCr-Cr 3C 2 ratios were prepared by microbeam plasma cladding technology. The influence of the NiCr-Cr 3C 2 content on the microstructure, mechanical properties, and molten salt corrosion resistance of CoNiCrAlY was investigated. The CoNiCrAlY with a 25 wt.% NiCr-Cr 3C 2 (NC25) cladding layer possessed the highest microhardness (348.2 HV 0.3) and the smallest coefficient of friction (0.4751), exhibiting great overall mechanical properties. The generation of protective oxides Cr 2O 3, Al 2O 3, and spinel phase (Ni,Co)Cr 2O 4 is promoted by the addition of 25 wt.% NiCr-Cr 3C 2, which significantly reduces the corrosion of the cladding layer, and this effect is much more obvious at 950 °C than that at 750 °C. Furthermore, its corrosion mechanism was clarified. From the findings emerge a viable solution for the design and development of new high-temperature corrosion-resistant coatings. Abstract Corrosion of the molten salts Na 2SO 4 and NaCl has become one of the major factors in the failure of steel components in boilers and engines. In this study, CoNiCrAlY cobalt-based cladding layers with different NiCr-Cr 3C 2 ratios were prepared by microbeam plasma cladding technology. The influence of the NiCr-Cr 3C 2 content on the microstructure, mechanical properties, and molten salt corrosion resistance of CoNiCrAlY was investigated. The CoNiCrAlY with a 25 wt.% NiCr-Cr 3C 2 (NC25) cladding layer possessed the highest microhardness (348.2 HV 0.3) and the smallest coefficient of friction (0.4751), exhibiting great overall mechanical properties. The generation of protective oxides Cr 2O 3, Al 2O 3, and spinel phase (Ni,Co)Cr 2O 4 is promoted by the addition of 25 wt.% NiCr-Cr 3C 2, which significantly reduces the corrosion of the cladding layer, and this effect is much more obvious at 950 °C than that at 750 °C. Furthermore, its corrosion mechanism was clarified. From the findings emerge a viable solution for the design and development of new high-temperature corrosion-resistant coatings. Keywords: Co-based cladding layer; NiCr-Cr3C2; molten salts Na2SO4 and NaCl corrosion; friction