As an important light absorbing material, space extinction black paint has been widely used for space stray light suppression structures. This is usually not compatible with the Lambert diffusion law. Therefore, in order to describe the light scattering characteristics of a stray light suppressed structure surface accurately, bidirectional reflection distribution data at different angles and wavelengths are obtained by experimental measurements. Then a multivariate and multiparameter spectral bidirectional reflection distribution function model is established according to the characteristics of experimental data, and the parameters of the model are fitted accurately based on the Newton descent method. The quantitative evaluation of model error is completed by comparatively analyzing the measured data and the model data. The calculated model error is 3.07%, which proves the accuracy of the proposed parametric model. This model can provide important technical support for the design and evaluation of a space stray light suppression system.