In order to improve the service life of the grilled board of the grate cooler, the laser surface alloying technology is used to prepare an alloy layer on the surface of the ZG40Cr25Ni20 anti-wear and heat-resistant steel. Under the optimal process parameters, the surface of the grilled board is continuous and smooth without pores and cracks; the alloy hardened layer forms a good metallurgical bond with the substrate; The microstructure of the alloy hardened layer from the surface to the bottom is equiaxed crystals, dendrites and columnar crystals in sequence; The average hardness of the laser alloy hardened layer is 840 HV, which is about 1.6 times that of the matrix. The installation experiment of the cement plant shows that the service time of the grate slab after laser alloying has been prolonged by more than one time on average.