光谱辐照度是光谱辐射计量中最基本的参数，是研究各种辐射源及光电探测器特性的重要依据。为提高光谱辐照度的测量精度和量值溯源等问题，国防科工委光学计量一级站采用BB3200K高温黑体作为基准的辐射源，以新型辐射测温法为基础，通过一系列光辐射理论和几何原理推导出辐射温度与辐射光功率之间的关系；通过对光辐射功率的绝对测量，并结合低温辐射计，从而完成了光谱辐照度量值的精度测量。该理论奠基了以探测器为基础的新的光辐射量传体系。主要介绍了在光谱辐照度标准装置的项目中复现光谱辐照度所建立的数学模型及新的测试方法，给出了测量结果，并简要介绍了基于该理论的测量装置的组成及原理。

Spectral irradiance, which is the most elementary parameter in spectral radiation metrology, is the important foundation on studying the characteristics of all kinds of radiating sources and optoelectronic detectors. In order to improve measurement precision and traceability of spectral irradiance quantity value, the optical metrology station uses BB3200K high temperature black body as a fiducial source and adopts the new method for measuring the radiation temperature. We derived the relation between radiation temperature and radiation power by making use of a series of radiation theories and geometry principle. The precision quantity value measurement of spectral irradiance is realized by absolute measurement of the radiation power by means of a cryogenic radiometer. The measurement results are shown in the paper. The theory laid the foundation for the new detectorbased quantitytransfer system. This paper mainly introduces the new measurement method and math model about measuring spectral irradiance. At the same time, the measurement device and measurement principle are introduced.