Abstract: With the optimization of the final mining limit of open-pit mine, the planning of material flow, stripping engineering deduction, propose and study the dynamic design and optimization of medium and long term schedule, need to open pit mine existing 3d geological model of the multistage discrete refinement, and the traditional segmentation and Boolean operation of the ground mode can hardly meet the needs of the multilevel discretization.. In this paper, the mining block model and mining model are defined, and a based on ternary DEM open-pit coal mine closed shell envelope voxel modeling method, model of coal and rock ternary DEM refers to the top, bottom and side DEM, ternary DEM after curing the coal and rock can generate the corresponding closed shell envelope voxel model. The model between entity model and the block model, can very good protection to calculate quantity accuracy, have higher Boolean operation efficiency at the same time, can be the reality that decide a dot, the size and structure of the directional cutting, on the basis of the traditional calculate to mould, through specific structure definition, rich stripping process and process parameters, such as technical indicators attribute, customize the exclusive mining model, It can better serve the demand of dynamic optimization problem of open pit mine.