Abstract:The SCADA System of 750KV EHV substation bears multiple important functions such as remote control function, automatic control function, measurement meter function, interface and system use, relay protection and related functions, and its operation status can directly concern whether the power grid system can work safely and stably. The on-site operating experience shows that the system link defects, ie, communication interruptions, server downtime and network storms, are the main factors that cause anomalies of substation’s SCADA system. This paper has analyzed the three defects mentioned above. Besides, it also explores the substation SCADA system based on edge computing by combining the“three-tier and two-net” structure with edge computing.Moreover, it elaborates the significance of the SCADA system based on edge computing through making a comparison over process of remote control between existing comprehensive self-system and SCADA system based on edge computing, which will provide reference and theoretical basis for the research of 750KV EHV transmission system intelligent substation SCADA system.