Abstract: The dump of open-pit coal mine is mixed with soil and gangue.The fire has the characteristics of uncertain spontaneous combustion position, sudden change of spontaneous combustion boundary temperature, strong correlation with high slope and overburden thickness.In order to study and solve the fire problem of dump, taking the south dump of Antaibao Open-pit Mine as an example, the fire characteristics of dump were analyzed and summarized.The spatial distribution of fire was identified by means of high-altitude temperature survey, surface exploration hole temperature measurement, underground borehole temperature measurement and other technologies, and a systematic fire detection technology of “ air-ground-depth ” was established.By improving the systematic fire extinguishing technologies, such as setting of fire wall, combined with deep grouting, shallow Tianzigou grouting, as well as triple slope surface sealing technologies such as grouting sealing, effective compaction of new and old overlying soil, and external soil spray spreading, a comprehensive firefighting and reburning prevention technology system suitable for large area, high slope and deep fire is constructed, while avoiding large-scale excavation and ensuring environmental protection and safety.It has been verified and improved through the construction practice of the test area.