In Dongguashan Copper Mine,the ore body occurs in about 1 km beneath the earth surface,the tectonic stress is very complex,the geostress is high,and open stoping with subsequent full tailings cementation filling is adopted.Based on the results from laboratory experiment,the forces on the cemented full tailings filled in high and large mined-out area was theoretically analyzed using Terzaghiand method and Thomas method,the stress distribution of backfill and surrounding rock was studied by use of FEM,and the diverse failure zones due to excavation disturbance in the surrounding rock of stope were determined.