Abstract: Based on the condition of the nearly flat coal seam of the working face of Bulianta Coal Mine, on the basis of analyzing mining affecting factors, the mining height, working face length and mining speed were selected. Using the orthogonal experiment design to establish FLAC^3Dnumerical model, overlying rock influence sensitivity and overlying rock damage extent were analyzed. The results show that the mining height has the greatest sensitivity to the overlying rock influence, and the mining speed has the greater sensitivity than working face length by variance analysis; according to the contradiction of modern coal mining and water resources shortage and ecologically fragile in Shendong Mining Area, knowing overlying rock movement regular and adjusting mining systems appropriately can effectively protect the loss of the underground water and control overlying rock movement.