The sites were selected based on SRTM elevation data to effectively extract the locations where the electromagnetic wave was obstructed by surface features when the weather radar was placed at 0.5°, 1.0° and 2.4° in line with the working mode and detection principle of the weather radar. The obstructing conditions of surface features under the 3 elevations were obtained by means of elevation lattice data, so as to make SRTM data more precision and increase its arithmetic speed. The blind angle diagram of the sites, diagram of iso-beam heights and data at the elevations of 1 km, 3 km and 6 km at the site were finally obtained. This method fully reflects the high resolution characteristics of SRTM data. Finally, by combining with GIS map, the analysis on environment detection by using weather radar network in Sichuan which was taken as an example was finished. The analysis results at each site were provided.