Abstract: To protect underground water resource and rationalize the mineral resource，the measures which adopt totally closed curtain grouting to block groundwater are stable and effective to ensure exploitation of underground ore deposit.During the tunnel construction and ore mining，water drainage for surrounding rocks within curtain is required.With the water drainage ongoing，both inside and outside of the curtain will produce a certain hydraulic gradient，which will negatively affect the stability of the curtain area.By combining the water plugging curtain grouting engineering of Zhongguan iron mine，a three-dimensional geological model，3D visualization model and 3D mechanical model of the water shutoff curtain area was established based on hydrogeological data，engineering geological data and drilling data.Then，stress response caused by water drainage within the curtain wall rock is analyzed.The results showed that:water draining makes the stress field in plugging curtain region change obviously，and brings a great disturbance in west side and southwest side of the curtain.

Key words: Grouting curtain, Water drainage, Numerical simulation, Stability analysis