Abstract: This paper addresses issues such as malfunction, response delays, and communication instability in relay protection devices during the actual operation of coal mine power supply systems, proposing a modular optimization design scheme.By adjusting the setting curves of protection devices and employing wavelet transform and support vector machine algorithms to enhance fault diagnosis capabilities, the communication transmission links are optimized to reduce system delays.Additionally, dynamic load adjustment and global monitoring are achieved through the SCADA system.Field test results show that the optimized scheme significantly improves the response speed and diagnostic accuracy of protection devices.The short-circuit fault clearance time is reduced from 9.92 s to 3.15 s, system recovery time is shortened to 4.80 minutes, the malfunction rate is reduced to 2.01%, and communication delay is decreased to 52.12 ms, effectively enhancing the stability and operational efficiency of the coal mine power supply system.