For the serious destruction of the terrain in the earthquake area after the Wenchuan earthquake,the original topographic map and DEM data are no longer time⁃effective,which can not accurately describe the geological characteristics,and need to be updated and reconstructed urgently. 20 Envisat ASAR images from August 2007 to July 2010 ARE collected,the DEM in the study area is extracted by using multi⁃baseline InSAR technology,and the generated ASAR DEM is compared with ASTER GDEM and SRTM DEM. The exper⁃ imental results show that ASTER GDEM ...