Abstract: The delineation of mining boundary is the basis of open-pit mining design，the results of boundary optimization directly restrict the overall development benefits of the mine.Due to a series of non-linear dynamic problems such as complex and changeable geological rock mass，disordered grade distribution and changeable economic parameters are existed in the mining process of open-pit mine.However，the above problems are not effectively considered by the major boundary optimization method.In order to realize the economic dynamic evaluation of open-pit mine boundary optimization and mine stripping equilibrium，combing with the optimization of open-pit boundary with geological grade and occurrence stage of orebody，based on geological database，three-dimensional solid model and block grade model of orebody are established by using SURPAC software.Meanwhile，with the aid of boundary dynamic optimization analysis software Whittle，and combined with the specific situation of a mine，a series of open-pit boundary optimization schemes are proposed by combining floating cone method with LG graph theory under certain technical and economic conditions.According to the design and production scale of the mine，schedule production for each boundary scheme is done，and consider the time value of the fundsthe discount rate is introduced，the maximum net present value （NPV） of each scheme after comparison is obtained.The scheme with the largest net present value （NPV） is determined to be the optimal one. The study results show that the efficient dynamic optimization of open-pit boundary under dynamic conditions is realized by using the optimization scheme proposed in this paper，which can also provides a new idea for the optimization of open-pit mining boundary.

Key words: Open-pit mining, Open-pit boundary dynamic optimization, Three-dimensional solid modeling, Floating cone method, LG graph theory, Net present value