Abstract: On June 12, 2020, a rainstorm and waterlogging accident occurred on the high-voltage transmission line of Sencong line in Conghua district, Guangzhou city, resulting in collapse and waterlogging accidents in many tower areas. The study should use SBAS technology and based on the Sentine-1A data to obtain the regional surface shape variables from January to June in 2020 in the north of the chemical industry. The influence of heavy rainfall on the surface deformation of mountain body is studied. The comprehensive analysis and monitoring results show that most of the areas tend to be stable in the meantime, and some hilly areas are affected by external conditions and under the influence of high soil water content, it presents an unstable and continuous settlement trend. In the season with the heavy rain, the surface settlement rate will increase significantly, and the maximum settlement is more than -55.3 mm in the meantime. The seasonal heavy rainfall and human frequent construction activities brought by subtropical monsoon climate make landslides, waterlogging and other natural disasters prone to occur, which have a negative impact on regional environmental stability and security, regional development as well as the economic growth.

Key words: settlement observation, InSAR, SBAS, high-voltage transmission line, security check