A NiCoCrAlY coating has been prepared on Hastelloy N substrate by the powder-feeding laser cladding technique. The corrosion behaviors in molten LiF-NaF-KF salt at 900oC for 100h are studied for both the substrate and the coating. The corrosion resistance in molten FLiNaK salt is evaluated by the corrosion weight loss method, while the microanalysis on phase constitution, morphologies and compositions are carried out by XRD, SEM and EDS. The results show that, the corrosion rate of the NiCoCrAlY coating is merely two thirds that of the Hastelloy N substrate. The substrate is characterized by intergranular corrosion and the element Cr was selectively corroded along the grain boundary. The origin Hastelloy N is consisted of γ-Ni and Mo, and a new Cr1.12Ni2.88 phase is precipitated after the corrosion test. The NiCoCrAlY coating exhibits a homogeneous corrosion feature, in which the element Al diffuses outwards and the corresponding Al-rich corrosion products act as the barrier and thus protect the substrate by impeding the diffusion of other elements. The laser-cladded coating is consisted of γ-Ni, AlNi3 and Al0.983Cr0.017, and only γ-Ni retains after the corrosion test. The corrosion resistance of Hastelloy N in molten FLiNaK salt is greatly improved by the laser-cladded NiCoCrAlY coating.