Abstract: To investigate the spatial-temporal variation characteristics of ground deformation in Jiulong River Estuary area, this study development laws and causes of land subsidence in this area used the Small Baseline Subset Interferometric Synthetic Aperture Radar (SBAS-InSAR) technique and the Permanent Scatters Interferometric Synthetic Aperture Radar (PS-InSAR) technique to obtain spatiotemporal distribution information and evolution patterns of ground deformation from January 2017 to March 2022. In addition, we conducted a comprehensive field investigation data and hydrogeological environmental data to systematically analyze the causes of land subsidence in the study area. Results show that both SBAS-InSAR and PS-InSAR methods consistently revealed that during the study period, the surface area of Jiulong River Estuary showed a subsidence trend as a whole, with an average annual subsidence rate of 6.2 mm/a based on the SBAS-InSAR analysis. According to the development law of surface deformation in time series, the subsidence center of the study area continued to expand and the subsidence amount gradually increased. During the study, the maximum cumulative deformation amount reached more than 250 mm, mainly distributed in the central and southern part of Fugong and the central and southern parts of Haicheng and Dongyuan and in regions of Southeastern Komei and Bangshan. Due to large amount of groundwater pumped for aquaculture in this area, the groundwater level has dropped, causing the silt layer to be consolidated, drained and compacted, and resulting in ground deformation.