Abstract: Taking the mining of the 2^# hanging wall ore in Daye Iron Mine by a filling method as an engineering background, the change of high-steep slope stability in the mining process was analyzed first in this paper. Then through using on-site monitoring together with similar material simulate experiments, the stress and displacement changing rules of rock pillars and surrounding rock were studied to discuss the effect of mining the hanging wall ore using the filling method on the surrounding rock stability. The results show that the average value of slope safety coefficient decreases from 1.274 to 1.005 after slope expansion and mining. This indicates that the slope stability is poor. Although the rock pillars and surrounding rock are stable currently, the existing mined-out areas must be filled to change the stress concentration state before the mining of pillar ore and the roof & floor ore.