Abstract: In recent years, Ground-based Synthetic Aperture Radar (GBSAR) has been widely used in surface deformation monitoring and large building deformation monitoring. Polar Format Algorithm (PFA) is a typical high-beam imaging algorithm for spotlight SAR, this paper applies the application of ground-based SAR to specific monitoring target scenes, and applies polar coordinate format algorithm to it, a ground-based radar data processing method based on polar coordinate format algorithm is proposed. The imaging geometry of ground-based radar is established, the basic principle of the method is analyzed from the perspective of the phase history of the signal, and multiple compensation factors are introduced and the azimuth resolution is improved. Finally, the correctness and feasibility of the theoretical method are verified by simulation data and measured data.