Abstract: The thickness of Quaternary loose sediments in the city of Bayannur in the west of Inner Mongolia Autonomous Region is large, which provides basic conditions for the development of land subsidence. ALOS PALSAR (98 frames from 2007 to 2011) and RADARSAT-2 (10 frames from 2015 to 2016) are extracted to quantitatively analyze the land subsidence in the city of Bayannur, respectively, by using the PS-InSAR and SBAS-InSAR method for the first time, and field investigation is carried out to verify the reliability of InSAR monitoring results. The causes and development trend of land subsidence in this area are further analyzed, and important technical support for land subsidence disaster prevention and reduction are provided. The results indicate that (1) the land subsidence in the city of Bayannur exhibites a slow trend. The severity of subsidence is low and belongs to the stage of occurrence. (2) The subsidence rate was mainly concentrated in 0−10 mm/a from 2007 to 2011, and three concentrated land subsidence areas were observed: the Hanggin Rear Banner subsidence area (A), Linhe district subsidence area (B), and the water source area of development zone subsidence area (C). (3) From 2015 to 2016, the subsidence rate was mainly concentrated in 0−2.6 mm/a, and one concentrated land subsidence area was detected, that is, the Linhe district and north subsidence area (D), where the land subsidence is based on the Linhe district subsidence area (B), and continues to expand to the surrounding areas and the north. (4) The main influencing factor of land subsidence in the city of Bayannur is the groundwater level drop caused by the development and utilization of groundwater. Besides, the consolidation and compaction of the sediments is also an essential factor for the land subsidence in this area, and the increase in surface load has a certain promoting effect on the land subsidence.