The NiCrBSi coating was sprayed onto the 45 steel under a steady magnetic field. The microstructure, mechanical properties, and friction and wear properties of coatings were studied. In the steady magnetic field, the coating porosity decreases dramatically. No new phase forms, but the preferred orientation occurs for the γ-Ni, FeNi₃, and Ni₃Si₂ phases. Moreover, the magnetic domains within the coating become more active and more ordered with subtle variations in external magnetic fields. The microhardness of the cross section of coating increases significantly, the residual stress on the surface fluctuates obviously, and the wear amount of the coating decreases by nearly 13.6%. Results show that a steady magnetic field can improve the coating quality effectively. Besides, the mechanism of property enhancement of Ni-based coating by spraying under steady magnetic field was discussed.