Abstract: In order to solve the problems of gas and spontaneous combustion when old roadways threaded together in Getting Coal Mine with spontaneous combustion tendency, the study firstly analyzes old roadway gas component through drilling and sampling, and then studies the effect of the air pressure change on gas emission, and concludes that the pressure difference between the inside and outside of old roadway is the source of abnormal gas emission. After discussion and analysis, the study ultimately determined nitrogen replacement and gas drainage technology, which successfully guided engineering practice.