Abstract: A self-developed gas explosion system induced goaf spontaneous combustion was used to study the variation of methane products ignited by electric spark and high temperature source. The results show that after the two ignition modes detonate methane, the law of carbon dioxide formation is basically the same; low concentration methane explosion hardly produces CO. The volume fraction of CO increases with the increase of methane concentration when methane concentration is more than 9.5%. The volume fraction of CO₂ increases first and then decreases with the increase of methane concentration. The volume fraction of CO₂ is the largest when the concentration is 9.5%. The amount of CO generated by electric spark detonation is higher than that by high temperature source. The amount of CO₂ generated by high temperature source is higher than that by electric spark ignition. The way of CO generated by electric spark ignition is more sensitive when the concentration of CO is more than 9.5%. C₂ hydrocarbon gases, such as ethane, ethylene and acetylene, will be generated after detonating methane with a high concentration (more than 11.5%).