Relative radiation correction is one of the key technologies to realize high precision and full field radiometric calibration for the directional polarized camera. A high-precision and automatic method of relative radiation correction is proposed. 15×15 points vision field scanning measurements are used. The panoramic imaging measurements of radiation response are fulfilled through the integration of the high-precision and large two-dimension rotating platforms and large-diameter integrating sphere reference light source. On-orbit working mode is simulated, data collecting process is regulated, data acquisition software is written, and the acquisition of radiation response image data is fulfilled. Astitching algorithm for data image and a processing method for relative data are designed. The data processing and precision analyzing of relative radiation correction are completed. Results of data comparison analysis and accuracy analysis show that the precision of relative radiation calibration is within 0.5%～0.8%.