Abstract: In order to improve the safety and reliability of coal mine communication, an underground wireless communication system was studied. Radio frequency identification devices (RFID) technology was used at the underground ethernet cluster system, and IP phone was connected to LAN through the access point. This effectively transferred all the output from the terminal to the server in underground control room. Host system managed information after demodulation and decoding. Through network simulation test and the technical analysis, data transmission of our system was reliable, and it has advantages in signal cover, signal reliability and maintenance cost.