According to the official notification from Qamdo, Tibet on October 10, 2018, a landslide occurred on both banks of the Jinsha River in Boluo Township, Jiangda County, Qamdo, Tibet. The landslide was huge and blocked the main river channel, causing the water level to rise rapidly and forming a barrier lake. In order to investigate the location of landslide and the area of influence immediately, the researchers of the Institute of Geodesy and Geophysics of the Chinese Academy of Sciences (IGG,CAS) obtained the 1A radar image on October 4th (7:28:59) and 11th (7:20:51) from Sentinel respectively. Comparing the two disaster occurrence areas (Fig. 2), researchers found the landslide occurred in Rixi Village, Jianshe town, Baiyu County (Fig. 1b, blue arrow). The center position of the landslide body is 98°42'57 " E 31°04'53" N (Fig. 2). It can be seen that the landslide body almost completely blocked the main stream of the Jinsha River about 1.2km. In the downstream channel of the landslide body, the width of the river surface is reduced by 60 meters (measurement position is shown in Figure GCP3-GCP4, see yellow arrow in Figure 1(a)). In the upstream channel, after the landslide occurred, the river surface widened by 40 meters, indicating a rapid increase in water volume (see Fig. 1(c, d)). Studies have shown that the use of satellite observations play an important role in the rapid assessment of disasters.