Due to the limited uniform field breadth, the relative radiometric correction algorithm based on uniform field two-point can only be applied to narrow swath pushbroom sensor. An improved relative radiometric correction algorithm is put forward with remote sensing image based on uniform field. In the algorithm, the eligible radiance field is sampled from one image or multi images, and the relative calibration coefficients of the detectors in the selected regions and detectors among adjacent regions are calculated. The response of all detectors in broad pushbroom sensors is relatively regulated based on the calculated relative calibration coefficients of the detectors in the selected regions and detectors among adjacent regions. The results show that the algorithm can easily realize the correction of relative radiance in broad swath pushbroom sensors with good performance.