Based on DEM data in ArcGIS environment, the gradient, topographic features of the slope in Chanba basin, the flow direction, river network density and the number of rivers under different water catchment threshold were extracted. The results showed that the relation between drainage threshold and drainage density or watershed area followed a power-exponential function, and the higher the threshold value was, the sparser the network was. The optimum threshold value of the basin was 8000, which determined by the second order derivative, which avoided the subjective randomness. The best threshold of river network was extracted by ArcGIS nested software TauDEM, and the river network was stratified by Strahler method. The extracted river network matches well with Chanba natural water system. The topography and hydrology characteristics of the basin are in line with the general situation of the basin, which can be used as hydrologic model parameters directly to provide data support for the ecological environment management of Chanba River Basin. The method improves the efficiency of the hydrological model, and has the advantage of high precision and low cost.