Abstract: DC GIS/GIL is regarded as the key equipment in the layout of China's new power system due to its advantages of small size, large transmission capacity and stable operation. However, the current research and development applications of DC GIS/GIL is still facing challenges. It is susceptible to the influence of metal particles in the process of long-time operation and produces electric field distribution distortion, which in turn causes insulator surface charge accumulation and even triggers surface flashover, resulting in a significantly lower level of voltage withstand than that of AC GIS/GIL; moreover, the understanding of the mechanism of metal particles-induced surface flashover and the protection and management are imminent. Therefore, this paper focuses on the current DC GIS/GIL metal particles-induced surface charge accumulation to surface flashover stage process development mechanism, its inhibition and regulation methods and other research are sorted out, the typical behaviors of metal particles in the cavity of the DC GIS/GIL are summarized, and its impact on the surface charge accumulation and the surface flashover process and the role of the mechanism are explored. In view of the challenges faced by the current research on mechanisms and regulation means, corresponding technical paths and solutions are proposed, in accordance with the challenges faced by the current research on mechanisms and regulation tools, a staged research route from surface charge accumulation to surface flashover under the influence of metal particles is proposed, and the regulation strategy is guided by a flashover development model defined by a multi-parameter threshold, promoting the development of the theoretical system of flashover regulation at the air-solid interface of GIS/GIL, and providing a theoretical basis for the insulation design of DC GIS/GIL.