Abstract: In recent years, with the continuous development of urban construction, man-made or natural factors such as underground water extraction, subway construction, and volcanic eruptions have inevitably caused the settlement and deformation of the urban ground. Conventional methods of GPS measurement and precision leveling of land subsidence are difficult to meet the needs of large-scale and small-scale settlement of the urban ground. Synthetic Aperture Radar (InSAR) technology has the advantages of wide coverage, large range, fast data acquisition speed, monitoring of difficult-to-monitoring areas, and high monitoring accuracy. This provides a new method for urban land subsidence monitoring. However, studies have found that it is severely affected by time, space and atmospheric delays. PS-InSAR technology and SBAS technology have broken through this limitation, so they have played an important role in the work of urban land subsidence.