Both movement characteristics of the roof strata belonging to underground mining and slope stability of open pit when the remaining coal resources of open pit slope are recovered by underground mining in Antaibao open pit are studied by numerical simulation software FLAC3D. The results show that the evolution law of the compressive stress and compres-sive strain of open pit slope are shown by nonlinear decreasing trend as the different distance away from the ground stop line of open pit. Stress concentration of the roof is shown by asymmetric and compressive strain of the roof is reduced by nonlinear trend as the continuous underground mining. Tensile stress zone obviously biased the free end direction of open pit slope will be produced. Both the extrusion and movement caused by overlying rock and soil of open pit slope and the deterioration effect on the bottom rock mass of open pit slope caused by mining are the key factors leading to the open pit slope slip. There is a theoretical size for underground mining which can maintain the open pit slope safe and make the coal be recovered as much as possible.%运用数值模拟软件FLAC31对安太堡露天矿采用井工开采露天边帮剩余煤炭资源时的顶板岩层运动特点及边帮稳定性进行了研究.结果表明:随着距露天开采地面停采线距离的不同,边帮体内压应力、压应变均呈非线性减小趋势；随着井工开采的不断推进,其顶板内的应力集中呈不对称分布,顶板岩层变形也呈非线性分布；井工开采将促使边帮体内形成明显偏向边帮体自由端方向的拉应力区；可能导致边帮体发生滑移的主要因素将是边帮体上覆岩土体的挤压、推移与井工开采产生采动作用对边帮底部岩体岩性的劣化作用；存在着一个既使露天边帮保持安全、又可实现尽量多回收煤炭的井工开采理论尺度.
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