Abstract: 3-D vertexes of the round-brilliant-cut diamond are measured and calculated by the edge extraction,parameter space translation,line recognition and so on,according to the turntable image capture device.The geometric elements(such as the points,lines and surfaces) of the sample and their topology are connected by the multiple list data structure.The 3-D model about the round-brilliant-cut diamond is displayed by the vertexes and its topology.This method is very much fitted for the 3-D reconstruction of the faceted gems,as it can collect the images easily and calculate the data faster by computer.Furthermore,it could be applied to the cut evaluation,the optical effect simulation and the cut design of diamond/gems.