Abstract: Aiming at the existing problems of high response delay, large single point fault risk, heavy data transmission load and others in the traditional centralized coal mine power supply protection system, a type of distributed relay protection system based on edge computing architecture is studied and proposed. This system decentralizes the protection calculation and decision-making function to the edge protection units deployed besides equipment such as distribution switches, transformers and so on, a "cloud-edge-end" collaborative protection system is constructed. By building a semi-physical simulation platform, core indicators such as action time, selectivity, reliability and others of the system are conducted to be tested. The results indicate that the proposed system can shorten the average protection action time to within 20 ms, with a fault positioning accuracy rate of 99.8%, and has good hardware compatibility and long-term operational economy. The research results provide an effective technical approach for improving the rapid fault isolation capability and system reliability of coal mine power grid, and have a clear reference value for promoting the practical application of edge computing in mine power supply protection.