Abstract: In this paper, a refuge chamber monitoring system was designed to ensure the reliable operation of every system inside the refuge chamber. The monitoring system adopted PLC as the core, it collected relevant parameters in refuge chamber simultaneously, such as temperature, CO concentration and gas pressure of ventilation pipeline, and it automatically controlled air cleaner, spray system, oxygen devices and other equipments. PLC communicated with the monitoring equipment of the ground center station through the fiber optic cable. The practice showed that the ground staff implemented effective rescue command for the underground refuge chamber by using this system.