The light scattering and radiation characteristics of space target is related to its background environment, geometric structure and surface material, and also influenced by its attitude variation. The influence is especially prominent in spacebased surveillance. The influence of attitude variation on visibleradiation characteristics of space target is modeled on the basis of orbit theory, and the irradiance variation with attitude of HJ1 and ZY2 satellites is calculated by the given parameters. The calculation results indicate that the influence of attitude variation is not neglectable. The research could provide theoretical basis for space target detection and recognition.