Abstract: Coal mine gas concentration sensor directly collects on-site data, which is an important tool for analyzing underground gas hidden danger and judging the trend of gas disaster. According to the data of gas monitoring and monitoring since 2017 in Bijie coal mine, the time, place and reason of gas monitoring are statistically analyzed. It is found that the number of alarm times is concentrated in 7, 8, 9, November, and 8~17 in one day, and the coal mining face and coal mining face are the most easy to exceed the limit of gas concentration. There are 49.7% and 27.6% of the total alarm times, and the main reasons for sensor alarm are sensor failure and underground stop wind, and the field construction, such as blasting, drilling and roof collapse, is also an important cause of sensor alarm. According to the time, place and reason characteristics of gas monitoring and alarm, the train of thought for coal mine safety supervision and coal mine gas monitoring and management is put forward.