Abstract: Owing to the excellent corrosion resistance and workability, 316H stainless steel has emerged as a candidate material for core components in Generation IV nuclear reactors. However, its relatively poor wear resistance remains a key factor limiting its service life. The double-glow plasma technique was employed to prepare chromizing layers on 316H austenitic stainless steel. The influence of holding time, reaction temperature, and source voltage on the microstructure of the chromized layer was systematically investigated, and the hardness of the chromized layers was tested. The results indicate that during the plasma chromizing process, a Cr deposition layer initially forms on the sample surface. Subsequently, Cr undergoes inward interdiffusion, leading to the formation of the Fe-Cr diffusion layer. When the reaction temperature is 900 ℃, the prepared chromized layer has a dual-layer structure, consisting of an outer Cr deposition layer and an inner Fe-Cr diffusion layer. When the reaction temperature rises to 1000 ℃ or above, the diffusion of Cr sputtered onto the surface becomes sufficient, and the Cr deposition layer disappears, leaving only a diffusion layer of CrFe phase. At a reaction temperature of 1000 ℃, the thickness of the chromized layer gradually increases with the extension of reaction time, and the increase tends to be moderate after 3 hours. The source voltage primarily influences the supply of Cr, and as the source voltage increases, the thickness of the chromized layer gradually increases. To achieve good hardness of the chromized layer and enhance the wear resistance of the substrate, it is necessary to ensure that the thickness of the chromized layer is above 30 μm, and the Cr content in the chromized layer should be maintained to form a stable CrFe phase layer. And the surface hardness of the chromized layer reaches 900-1050 HV, which is 5 times of that of the 316H substrate.