Abstract:In order to solve the problem of surplus tailings stockpiling, ecological restoration is planned and implemented after the end of mining in the south of an iron mine. The hanging wall ore body is underground mining and application of sublevel open stopping with subsequent filling method. According to the engineering geological conditions of the south mining pit , the mining and filling scheme of the hanging wall mine, the dimensional numerical model of the south mining pit filling and underground mining is constructed to analyze the initial state of the computational model and simulate the filling process of the underground mining process of the hanging wall ore body. Firstly, according to the and mining technical conditions of ore body, stress, strain and plastic zone of roof under different lithology were studied and analyzed by numerical simulation method to evaluate the stability of stope and optimize the reasonable stops structural parameters. Finally, the influence of underground mining from backfill and no backfill in the south mining pit is simulated and analyzed. also, the stress and plastic zone changes of the open-pit slope and filling body in the hanging wall mine at different periods of underground mining are revealed. Through the comprehensive comparative analysis of the stress and plastic zone in different mining periods, it is suggested to strengthen the comprehensive monitoring of the stress and displacement of the open-pit slope, underground stope and roadway during the mining of the ore body in the -60m section.