Abstract: In order to study the requirements of space polarizing radiometer on measurement accuracy of degree of polarization,the influence of angular error of Wollaston prism on degree of polarization is presented based on the inversion of the polarization parameters and the method of the radiometric calibration.The results show that measurement errors of degree of polarization change with polarization state of incident light while keeping angular error of Wollaston prism fixed.Measurement accuracy of degree of polarization meets the specification of space polarizing radiometer if the angular error of Wollaston prism is less than 0.1°.