Abstract: In order to solve the problem of residual coal spontaneous combustion in the goaf of fully- machanized top coal caving mining face ,based on the analysis on the reaction process of the active group in coal,a fire prevention technology with high efficient retarding foam was provided based on the hydroxyI mode inhibitor and the ef fect investigation was conducted on the retarding performances. The inhibitor made the cross temperature of the coal samples delayed to 37.6 °C. The oxidation of the coa . | active group( methyl,methylene) could be restricted. A high efficient retarding foam fire prevention and extinguishing system was established and was applied to No. 4010 6 fully- mechanized top coal caving mining face in Dafosi Mine. The hidden fire sources in the goaf of the coal mining face was successfully extinguished. Within 24 hours, CO was controlled below 24 x 10- 6and there was no re- combustion phenomenon after the fire in the goaf extinguished.