Considering the demand for high-precision detection of SWIR remote sensing systems, the demand for the quantitative application of SWIR detection has increased in recent years. The change in inhomogeneity caused by shortwave infrared remote sensor was analyzed. The design scheme of non-point source blackbody calibration combined with star calibration in-orbit absolute radiation calibration; the actual development process of a remote sensing task; and the main influencing factors and optimization measures, including the optimization of the satellite calibration scheme, optimization of satellite blackbody temperature control, and star extraction algorithm, were analyzed. Based on the results of laboratory tests and estimation of the accuracy of the absolute radiation calibration, the evaluation results show that the calibration accuracy can meet the application requirements.