Abstract: Building numerical model based on actual mesostructure is a hot research field of rock-soil mechanics.According to the different inter structure,equivalence graph and edge vectorization methods are introduced.Taking the pore geomaterial made by ourselves and concrete CT images as examples,the steps of building model are shown.Analyses prove that it is easy to segment character areas when the image histogram has two or more peaks.When the image histogram has only one peak,top-hat mathematical morphology method can be used to enhance image,which make the segment easier.Equicalence circle or ellipse are placed for pore strucure in numerical model,while edge vectorization is applied to characterize the complicated structure.The results provide a method to build numerical model based on actual mesostructure.