Abstract: In the application of KJ90 type coal mine monitoring system in the Songzao Coal Mine, due to the factors of monitoring equipments, transmission lines and artificial destruction, the phenomenon of gas false-alarming is found when the actual gas emission at underground monitoring site does not reach the off-gauge alarm numerical values. According to the historical gas monitoring curve, the reasons lead to the gas false-alarming phenomenon are analyzed from different angles, at the same time, some targeted countermeasures are put forward, which provides a strong guarantee for safety production in coal mine.