Abstract: Xilinhaote fluorite mine was originally designed to use a 65° rock transfer angle to delineate security pillars.As mining continues to deepen, more and more ore resources are found within the delineation of the security pillars, resulting in a significant reduction in mining capacity, and seriously affecting the normal production of the mine.In order to solve this problem, on the basis of measuring the collapse range and accurately measuring the collapse angle, a new idea of using the mechanism of the critical bulk solid column to optimize the security pillars was proposed, this effectively solved the problem of excessive delineation of traditional security pillars, and avoided unnecessary waste of mineral resources.On-site application, the release of ore is about 51 thousand tons, with significant economic benefits.The security pillar optimization method can provide reference for mines with similar conditions.