Abstract: The sub-regional sublevel caving method was adopted in Xiaowanggou Iron Mine， which is divided into upper， middle and lower mining areas for simultaneous extraction along the direction of ore body. Under the long-term mining disturbance on pillars at the intersection of sub-region， the mining-induced fractures with different damaged condition were generated within the limits of 15~25 m from the boundary of mined-out area， resulting in the drilling pinching and increasing the difficulty of mining construction and recovery in the quasi-mining project. Summarizing the experience of pillar mining in upper and middle mining areas， based on the theory of loose pillar support， and according to the field monitoring results of the caving line at goaf approaching the arch shape and the inclination of the caving angle， the comprehensive technical measures of detecting the boundary of goaf by drilling， adjusting the mining sequence and the direction of mining approach， and increasing the support strength of roadway are put forward for the pillars in the middle and lower mining areas with high goaf height and long bearing time. These measures adapts to the mining-induced fissure condition， and makes the pillars at the boundary of caving zone safe and continuous mining.

Key words: Sub-regional caving, Intersection of ore-body, Mining-induced fracture, Safe continuous mining