Abstract: For problems of complex wiring, small network scale and short transmission distance of existing pressure monitoring system of coal mine underground hydraulic support, an online pressure monitoring system of underground hydraulic support was designed by use of WaveMesh wireless ad hoc network technology. The system collects pressure data of hydraulic support through wireless pressure sensor. Wireless monitoring substation receives the pressure data wirelessly and sends it to ground monitoring host through RS485 bus and optical fiber ring network. The application shows that the system runs stably and reliably, which can realize real-time and accurate monitoring of underground hydraulic support pressure.