Abstract:In the later stage of open-pit mining, when the deep has mine usually adopts from open-pit to underground mining method, in the process of exploitation of underground mine, deformation and failure characteristics of open-pit slope directly influence the safety of underground mining. To solve the problem, in the paper, through three dimensional numerical analysis, detailed analyzing the deformation and stress variation of open-pit slope in the process of underground mining. Some main research results are as follows: Vertical displacement changes at slope different elevation is relatively smaller in the -60m, -90m, -135m and -165m levels mining process, but larger in the -210m and -255m levels mining process. Underground mining mainly effects upper slope rock mass, its deformation value and scope are larger than that of lower slope rock mass. Under different mining levels, the concentration degree of maximum principal stress of the upper slope deep rock mass gradually increases along with mining level extension, and its influence scope also increases, while the minimum principal stress in mining level near significantly reduces.