In this paper, based on 36 scenes of Sentinel-1A image data covering the Tianjin area from 2017 to 2019,we used SBAS-InSAR method to study land subsidence monitoring area and achieve the annual average settlement rate and cumulative settlement Tianjin area. The SBAS-InSAR derived results were compared with leveling data. Finally, the spatial-temporal characteristics of subsidence in the region was analyzed. The results show that most of the regional surface deformation rate is in the range of -15 to 13 mm / a from 2017 to 2019,and the maximum subsidence rate of more than -130 mm/a,the largest settlement center is located in the town of wang qingtuo, xiqing district, Tianjin; the settlement results obtained based on SBAS-InSAR are compared with the level measurement results, and the accuracy reaches 2.96 mm; surface subsidence is obviously affected by factors such as groundwater exploitation, urban infrastructure development, industrial land use, and human activities.