Abstract: The gas anomaly pattern is studied from the angle of K-graph, at the same time, the abnormal mode of gas monitoring data is summed up. It is concluded that the coal and gas outburst is a big positive line, and the gas emission after the gun is two and three times positive. According to this, the diagnosis criterion of abnormal K-line of gas is established and the VB.NET programming language is used to compile the diagnosis program of abnormal K-line of gas. Through the mixed diagnosis of the abnormal K-line of gas in 105 different mines, the result shows that the accuracy rate is 93.33% and the universality is strong.