The work aims to improve microstructure and high temperature wear resistance of NiCrBSi coating. NiCrBSi coating was prepared on 45# steel by plasma spraying, then the coating was remelted by argon arc. Morphology, microstructure, composition and phase of sprayed coating and remelted coating were analyzed by scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and X ray diffractometer (XRD). Hardness and elastic modulus of the coating were tested by microhardness tester and nano-indentor, and fracture toughness of the coating was calculated. Wear resistance of the sprayed coating and remelted coating was evaluated and compared by performing friction-wear test at room temperature, 300 ℃ and 500 ℃. Various elements of the remelted coating were uniformly distributed, and phase mainly consisted of γ-(Fe,Ni), Cr2B, Mn5Si2 andα-Fe. Structure of the remelted coating transformed from layered structure of sprayed coating to compact cast structure, and porosity was reduced from 7.2% to 0.4%. Metallurgical bonding was formed between remelted coating and substrate. Hardness of the coating was reduced from 724HV to 608HV after remelting, while the elastic modulus of remelted coating was increased from 161.15 GPa to 195.92 GPa, and fracture toughness was increased from 0.63 MPa?m1/2 to 7.18 MPa?m1/2. Remelting treatment improves microstructure of the coating, wear resistance of the remelted coating is better than that of sprayed coating at room temperature, 300 ℃ and 500 ℃. Both oxidation and spalling of sprayed coating are increasingly severe with the increase of temperature, while the remelted coating is not subject to obvious oxidation and spalling.