Abstract: The shrinkage mining method is adopted in the Xilinhaote fluorite mine. With the long-term exposure of goaf and the continuous disturbance of underground mining， the security pillars have been damaged to a varying degree， resulting in serious threats to the safe operation of the auxiliary shaft. In order to release this threat， FLAC 3D numerical simulation method is used to simulate and analyze the changes of stress and displacement near the auxiliary shaft before and after the excavation and filling of the security pillars in the fourth and fifth middle section. This confirmed that the excavation threatened to the shaft and the filling was beneficial to the shaft protection. Based on this， the stabilization measures for security pillars with combination of the subsequent caving of the middle retained pillars and the synchronous waste rock filling to the surface collapse pits was put forward. In addition， a secondary backfilling was performed for the remained goafs in the filled pillars. The effective filling at the damaged zone of the security pillar can be realized. This may provide a powerful guarantee for the safe， green and efficient mining.

Key words: Security pillar, Numerical simulation, Pillar stabilization technology, Surface filling