The safety of the nuclear power has become the main problem in the development, and the failure of structural materials caused by corrosion is one of the main reasons for the safety problems. In order to improve the corrosion resistance of 304 stainless steel, which is a candidate material for molten salt reactor, Hastelloy C276 coating and C276 coating with 1.0% (mass fraction) Y2O3 were cladded on the surface of 304 stainless steel by laser cladding technology. The microstructure, phase composition, hardness and resistance to FLiNaK molten salt were studied, respectively. Results show that the two cladding layers are well combined with the substrate. The microstructure of C276 cladding layer is composed of equiaxial, secondary dendrite, cellular, columnar and planar grains from top to bottom, and the average hardness is 297 HV. After Y element was added, the microstructure of the cladding layer does not change obviously, and the hardness of the cladding layer decreases slightly. After static corrosion at 700 ℃ for 20 h in FLiNaK molten salt, 304 stainless steel exhibits obvious intergranular corrosion and Cr element loss and the corrosion depth is 30 μm. The corrosion depth of C276 cladding layer is 16 μm and the corrosion depth is about 8 μm after Y addition. The corrosion resistance of the laser cladding C276 coating in the molten salt is greatly improved compared with that of the 304 substrate.