Abstract: To solve the problem of spontaneous combustion in the gob,a certain mine was taken as an example to build the computational fluid dynamics model.The software of Fluent was used to simulate the concentration percentage of carbon monoxide at different monitoring faces.Thickening fly ash carbon dioxide foam material is put forward to plug the gob and suppress fire and explosion.The results show that the place of the highest concentration of carbon monoxide lies 20 ～ 30 m away from the working face in the goaf.And the best position to grout is 20 m away from the working in the gob.Thickening fly ash carbon dioxide foam material can control effectively spontaneous combustion in gob.Research results can provide guidance for control techniques of fire in the gob.