Abstract: The high-precision extraction of hydrological characteristics,such as water system route,small watershed boundary and the position of pour point,is the basis and premise of accurate analysis of various hydrological characteristics. In order to solve the problem of low accuracy extraction results of hydrological feature based on low resolution DEM data（SRTM DEM,ASTER GDEM）,this study first obtains relatively high accuracy DEM with spatial resolution and altimetry precision based on InSAR technology and Sentinel-1A/SLC data,and then compares and analyzes the extraction results of hydrological characteristics for small watershed based on different DEM data sources. Finally,the main conclusions of this study are as follows:（1） Based on SRTM DEM,ASTER GDEM and InSAR DEM,the extraction errors of mean height of five sampling points are 8.1,8.5 and 3.7 m respectively,and the InSAR DEM has the highest accuracy.（2） Based on SRTM DEM,ASTER GDEM and InSAR DEM,the coincidence degrees of the six main water system routes are 74.12%,85.50% and 88.36% respectively,and the coincidence degrees increases successively.（3） The mean error between the actual position of pour point and the extracted position of pour point from SRTM DEM,ASTER GDEM and InSAR DEM are 4.93,4.69 and 4.63 km respectively,and the error decreases successively.