Abstract: The method on boundary circle composite cone of open pit posed in this article is a kind of new means on boundary circle of open pit which comes form traditionally handworking methods and floating cone methods of computer,it also is a inheretance and development of traditionally handworking methods and floating cone methods of computer.By designing different composite cones,one could get different conception of peel-pick ration, including boundary peel-pick ratio,average peel-pick raio and producing peel-pick ratio.accodrding to specific conditon of mines,one can adopt accordingly decision-making principles and determine boundary.This method is applicable in any kinds of boundary circle of open pit.