Abstract: This article proposed distributed optical fiber temperature detection technology to monitor the coal spontaneous combustion of large angle thick and multilayer flammable coal mining goaf.According to the adjacent working face goaf division of "three zones" results,the calculation results of coal spontaneous combustion point temperature range,the actual situation of temperature host channel capacity situation based on raman scattering theory,we laid optical fiber reasonably,connected the host to the PC via the underground loop network,and displayed the real-time temperature curve on the KJ95N safety monitoring system interface of each channel when the working face moved forward to the stop line of the upper layer or the open-off cut of lower layer.We simulated the distribution laws of temperature field of goaf by ANSYS FLUENT and verified steep coal seam vertical situation of "three zones",which is coincide with distributed optical fiber temperature measurement results. The observation results show that distributed optical fiber temperature measurement system can reflect the situation of spontaneous combustion of coal in goaf,which is suitable for gob temperature monitoring.