In view of the underground monitoring and monitoring system of coal mine, wired data transmission has been used in the past, but there are some disadvantages such as complicated wiring work, large amount of labor, fixed network structure which is not convenient to meet the dynamic requirements and low stability. Therefore, this study designs a monitoring system based on ZigBee wireless sensor network, wireless transmission, strong mobility, high reliability, low power consumption, strong real-time performance, etc, can be real-time monitoring of the coal mine environment parameters, including downhole temperature, humidity and gas concentration, and the acquisition of information sent by ZigBee wireless transmission way. STM32F103RBT6 is adopted as the wireless network processor in the system, which is responsible for establishing the network and transmitting data. NDIR HC sjh-5 CUBIC gas concentration sensor to collect underground mine data; Wireless SZOS embedded wireless communication module is used as the wireless sending and receiving port to enhance the wireless sending power. The software architecture adopts ZigBee protocol stack. The research shows that the proposed ZigBee wireless sensor network based coal mine underground gas monitoring system can help improve the real-time monitoring level and reduce safety risks in the complex and special environment of coal mine underground.