Abstract: G-matrix inversion method is a commonly used image reconstruction algorithm for one-dimensional aperture synthesis radiometers, and its implementation includes two key elements: system response G-matrix calibration and effective numerical inversion algorithm. At present, the calibration method of systematic error step-by-step measurement is used for the radiometers on orbit. Based on the theory of G-matrix inversion method and G-matrix point source measurement a, this paper introduces the corresponding point source measurement test process and water imaging test process, analyzes the imaging accuracy, and verifies the feasibility of overall calibration. Then proposing the on-orbit calibration method of G-matrix, and the influence of satellite maneuvering on the load is analyzed. Compared with the calibration method of step-by-step measurement system error currently used on orbit, the method proposed in this paper uses external calibration source to calibrate the system response G matrix, which can simplify the calibration process of step-by-step calibration of various system parameters, achieve imaging accuracy in accordance with the design and ensure the realization of subsequent high-precision image reconstruction algorithms, provide a new idea for one-dimensional synthetic aperture radiometer on orbit calibration.