Abstract: In view of problem that underground monitoring devices are mainly influenced by electromagnetic interferences of medium and low frequency band, main electromagnetic interferences of medium and low frequency band of coal mine underground, namely surge interference of underground power cable, interference of power frequency converter, interference of grounded grid, radiated interference of motor and electrical devices, interference of trolley locomotive and interference of leakage communication system, were measured and analyzed with oscilloscope and spectrum analyzer. The analysis results show that the surge interference of power cable, interference of power frequency converter and radiated interference of motor and electrical devices are bigger than the others, the next are the interferences of grounded grid and trolley locomotive, and the one after the next are the interference of leakage communication system and the power interference of power cable.