The relative radiation correction method for large field of view polarization imaging instrument was discussed. According to the inversion order of the physical quantity of the incident light restored by the detection signal， the relative radiation correction method of the large field polarization imaging instrument based on single pixel radiation response model is proposed. The detector correction， spatial stray light correction， polarization correction and optical system relative transmittance correction are carried out in turn. During the on orbit test， a fast validation method of multi angle observation data based on desert field reflectance method is designed to meet the detection requirements of large field of view polarization imager. The experimental data show that the difference of single point radiation response is less than 4%， and the relative radiometric correction method is reasonable and effective， which provides data basis for on orbit radiometric correction using large amount of statistical method. The method of relative radiometric correction and on orbit fast test provide effective reference for the follwing polarization imaging instruments with large field of view.