Abstract: Air plasma spray technique was used to prepare Fe-Ni-B coating on 1Cr18Ni9Ti stain steel substrate and the Fe-Ni-B coating was re-melted.The microstructure of Fe-Ni-B coating and interface con-figuration before remelting was analyzed using SEM and EDX apparatus.The micro hardness,thermal shocking performance,adhesion strength between coating and substrate was also studied.The results indicated that after the remelting,the coating microstructure became more compact,and diffusion and new ingredients appeared between the interfaces of coating and substrate,so the thermal shocking performance was improved.The adhesion strength between Fe-Ni-B coating and 1Cr18Ni9Ti stain steel substrate is 36.3MPa and micro hardness distributes at 470~570HV_0.2.The micro hardness of substrate near the coating is higher than that of the farside because of the thermal influence of spraying particles,however,the micro hardness of interface is relative low.