During bench blasting in open-pit mines,the surface profile of the muckpile and the movement trajectory of the internal particles are important influencing factors for precision mining in open-pit mines,especially for ore bodies with uneven mineralization.Aiming at the problem that the three-dimensional distribution of the muckpile spatial profile is a difficult problem in the evaluation of the blasting effect of open-pit mines,this paper proposed a calculation method based on discrete element and carried out the calculation and analysis of the bench blasting muckpile profile by relying on the Yuanjiacun Iron Mine of Taiyuan Iron and Steel Co.,Ltd.This method first used three-dimensional laser scanning to scan the joints in the area to be studied to obtain joint occurrences,and tested the mechanical parameters of the rock mass; then,the joint distribution model is established according to the statistical results,and the single-hole blasting charge and initiation mode are combined to carry out blasting calculation simulations.During the calculation process,monitor the cells near each blasting point,determine the motion trajectory of each particle,and determine the three-dimensional profile of the muckpile; finally,the accuracy of the numerical results is verified by comparing the actual shape of the muckpile with the slope angle.The results show that the height,impact distance and rupture angle of muckpile calculated by numerical analysis are in good agreement with the actual data measured by UAV.The simulated forward thrust distances of No.1 and No.2 in the muckpile are 26.1 m and 14.71 m,respectively,while the forward thrust distances of No.5 and No.6 are 9.18 m and 9.83 m,respectively,and the movement is relatively gentle.Through the numerical analysis of the space form of muckpile,it can provide a theoretical basis for the precision mining of open-pit mine.