Abstract: In order to reveal the influence mechanism of bacteria on CO disappearance in sealed goaf, an experimental device of bacteria effecting on CO has been developed autonomously. By contrast experiment, the change law of CO and CO2 of coal samples was analyzed in sealed space under the condition of air sterilization before and after, coal samples sterilization before and after and water sterilization. The results show that the presence of bacteria could play a role in the disappearance of CO, and the influence mechanism of bacteria on the disappearance of CO had been inferred. The research results and ideas provide reference for the accurate prediction of sealed goaf.