This paper is the result of environmental geological survey engineering. Objective Land subsidence is one of the main geological hazards in coal mine area, which seriously affects the sustainable development of mining economy and the safety and stability of residents' life. It is necessary to conduct rapid and efficient monitoring of land subsidence in the mining area. Methods Taking Datong coalfield as an example, the 31 scenes Sentinel-1 images acquired from January 2020 to December 2021 were used to monitor the land subsidence based on Small Baseline Subset InSAR (SBAS-InSAR) technology. The land subsidence rate and cumulative subsidence results of Datong coalfield were obtained. Moreover, the reliability of the monitoring results was verified using existing research results, and the spatiotemporal variation characteristics and evolution laws of subsidence were analyzed. Results The results indicate that the land subsidence in the Datong coalfield is extensively distributed, and its overall distribution of subsidence is basically consistent with the trend of mining management data. The subsidence is mainly distributed in the west of Nanjiao County of Datong City and the junction of Datong City, Huairen City and Shanyin County, among which the land subsidence of Tashan mine is the most severe. The subsidence characteristics of Datong coalfield mainly include the maximum subsidence rate of 168.03 mm/a, the maximum cumulative subsidence amount of 329.12 mm, and the total subsidence area of 270.95 km². Overall, there is a continuous increase in subsidence, and it takes a significant amount of time to achieve relative stability in surface activities in accordance with this trend. Conclusions This study shows the feasibility of InSAR technology in subsidence monitoring in coal mine area, which can provide a new technical for mineral resources management work, and the research results can provide scientific basis for subsidence monitoring and warning, disaster prevention and control, and rational development and utilization of resources in coal mine area.