Ground-based synthetic aperture radar (GB-SAR) has been proved to be one of the cutting-edge techniques for the timely detection of slope failures in both natural and engineered slopes. This paper focuses on the structure deformation monitoring on the dams using GB-SAR data. Temporal sequence data was collected by ground SAR equipment from 29 July to 1 August for the Geheyan dam and the SAR images with high quality were selected through the exhaustive spatial-temporal coherence analysis based on permanent scatterer (PS) theory in this paper. A practical solution for dam structure deformation extraction after the atmospheric effect reduction is proposed in depth. The deformation of the dam spillway gates is greater than that of the dam body monitored by this GB-SAR campaign, and with the increase of the water level in the reservoir area, the displacement increases along the direction of water flow gradually. The surface deformation rate of the dam body is fitted by linear regression analysis, and the interpolated rate results are compared and verified with the plumb line measurements. Finally, the consistency of the dam deformation average rate based on the PS time series analysis technology by GB-SAR and plumb lines is verified in this article, demonstrated the excellent performance of the proposed method for remote multipoint displacement measurements of the dam.