Objective To study the hot corrosion behavior of the NiCrBSi-TiB2 coating in molten Na2SO4-30% K2SO4 salt at 800 ℃. Methods The nanostructured NiCrBSi-TiB2 coating was sprayed on the surface of carbon steel by high velocity oxy-fuel (HVOF), and its hot corrosion behavior at 800 ℃ was investigated using saturated Na2SO4-30% K2SO4 solution as the corrosion medium. Results The micron coating had coarse grains, and the diffusion coefficient of Si was low, which easily led to the formation of Si-depleted Cr-rich layer, and the Cr2 O3 film formed had relatively low solubility in basic molten salt, which could well protect the coating. Conclusion The micron coating had higher resistance against hot corrosion in molten Na2 SO4 -30% K2 SO4 salt.