According to requirements of water supply of underground high-pressure dustfall system, the papper developed a monitoring device of underground high-pressure dustfall water supply system based on PIC18F4580 single-chip microcomputer, introduced hardware and software design of the device. The device can real-timely monitor water level, pressure, running status of tank, and can incorporate these protection status information into mine monitoring network through CAN bus interface and conversion unit, so as to realize remote monitoring. The experimental results showed that the monitoring device reaches design requirement and can guarantee real-time monitoring and safety operation of high-pressure dustfall water supply system.