Sherardizing process is a kind of thermal diffusion surface modification technology, which lets the sherardizing agent and steel parts contact at high temperature, and forms an alloy protective layer on the surface of the parts by the atomic diffusion. As a simple, environmentally friendly and efficient surface anti-corrosion treatment process, the sherardizing process can effectively improve the wear resistance, corrosion resistance and oxidation resistance of metal materials, et al, and has received attention of researchers due to broad application prospects. The formation mechanism of powder zinc layer was analyzed, and the structure of the layer was emphatically discussed. Then, the influence of temperature, time and alloy elements on the formation of zinc layer was summarized. Researchers have found that prolonging the holding temperature and time is beneficial to the increase of the thickness of the layer, but should be controlled reasonably. Too high temperature or too long time not only makes the performance of the layer worse, but also increases the energy consumption and reduces the productivity. What’s more, the properties of zinc layer can be improved by adjusting the amount and kinds of alloying elements. However, the optimum addition amount of various elements and the modification mechanism of the elements on coating need to be further explored. Due to the low efficiency of powder zinc process, mechanical energy and nanotechnology can be applied to the sherardizing process to effectively improve the efficiency of the process and the performance of zinc layer. Finally, based on the current research situation, the research direction of the sherardizing process is discussed.