Abstract: Abstract: Aiming at the potential fire hazard outside the goaf of 1715 fully mechanized top coal caving face in Honghui No. 1 coal mine, the specific caving situation of the working face is analyzed from the perspective of temporal and spatial evolution, the dynamic distribution model of porosity and permeability in the goaf of the working face is optimized, and the three zone range and air leakage of the goaf in different stages are calculated combined with COMSOL numerical simulation software, The space-time combined fire control measures suitable for the working face are put forward. The results show that when the total distribution air volume is certain, the "three belt" range of "two in and one return" W ventilation mode is smaller than that of u ventilation mode, and the air leakage of the latter is more serious and the hidden danger of spontaneous combustion is greater; After adopting the W-type ventilation mode of "two inlets and one return", with the increase of total air distribution volume, the range of three spontaneous combustion zones increases and extends to the deep part of goaf. Finally, it is determined that the air distribution scheme of 300m3/min air inlet roadway and 400m3/min auxiliary ventilation roadway is the best ventilation scheme during fire control of the working face, and the self combustion area is the narrowest; According to the time-space joint prevention and control technical scheme, the field verification was carried out in the working face, and the potential fire hazards outside 1715 working face were effectively solved. It has important reference significance for similar fire control in China.