Abstract: It is the guidance to scientifically determine the combustion scope of the coalfield outcrop fire area for proposing more reasonable and reliable prevention and control measures basis for coalfield outcrop fire. On the basis of the analysis of the mechanism and range of the coalfield outcrop fire area causing subsidence, we further study on the influence factors for the fire area subsidence range, such as the lithology of overlying strata, the inclination angle of coal seam, the burning depth of coal seam, the burning thickness of the coal seam, the burning quantity of the coal seam, and so on. This method for determining the scope of the fire burning is proposed on the basis of the three factors of coalfield outcrop fire burning, such as the movement of stratum, the ventilating system and the heat source of fire area.