Abstract: In view of the complex wiring, challenging maintenance, and limited flexibility of the wired monitoring system for various parameters in underground coal mines, a study was conducted on a low-power wireless sensor network based on UWB technology. The sensor nodes were designed using STM32L151 micro-controller and DW1000 chip, incorporating functionalities such as automatic networking, data multi-hop transmission, and distance measurement. The key technologies of low power wireless sensor network in coal mine were introduced in detail: network mechanism, sensor data multi-hop transmission technology and low power sleep algorithm. The test results show that the network access time of sensor node is proportional to the network depth, as each step of the network depth increases, the network access time increases by 1 digital transmission cycle. The sensor data transmission delay is less than 1 second, and the communication distance can reachup to 100 meters. The average working current is 230 μA when the node is not connected to the network, and 680 μA when it is connected. It provides a low-power consumption, low cost and high reliability data transmission channel and platform for coal mine safety monitoring system.