Abstract: Shaxi Copper Mine adopts the long-hole sublevel open stope and subsequent backfill mining method and the high-stage large-diameter long-hole caving mining method,which has the advantages of large production capa-city,low mining cost,and safe working conditions,but also accompanied by greater blasting vibration and impact.During mining in the two-step stope,the filling bodies on both sides are not only subjected to static loads but also obvious dynamic loads.Flac3D software was used to simulate the stability of the two-step stope side holes under different charging structures,analyze the dynamic response of the filling body sides under dynamic loads,and reveal the relationship between the charging structure of side holes and the stability of filling body sides,providing a basis for the selection of mine blasting scheme.