Abstract: In view of the objective conditions of high sulfur content and local enrichment, large amount of residual coal and closing to upper goaf of coal seams in the 8104 fully mechanized coal mining face of Xinwei Coal Mine, the distribution law of coal spontaneous combustion danger zone in goaf is studied. In the implementation process, we used beam tube monitoring system to test the gas field distribution in the goaf in real time. On this basis, “three zones” of the goaf of the 8104 fully mechanized mining face are divided by taking O₂ concentration change as the main index and the temperature change as the auxiliary index, and the numerical simulation method is used to compare and analyze the field test result. The result shows that the measured results are consistent with the numerical simulation results. Finally, the range of spontaneous combustion zone in the goaf of the fully mechanized mining face was determined: 40.5 m to 95.5 m on the inlet side and 15.3 m to 59.7 m on the return side.