Abstract: The commonly used BRDF function model in the active laser imaging system was analyzed in this paper. In order to further simplify the SUN model, real refractive index function was introduced to descript the characteristics of medium. On the basis of the traditional BRDF theory, a methed based on image analysis was proposed to analyze the BRDF values of targets in the active laser imaging system. Laser active imaging system was used to illuminate the target sample plate and image, and the target image was obtained by changing the angle between the target plate and the imaging system. The BRDF values of targets were calculated with the gray values of those images, and then the BRDF curves were obtained. Experimental measurement and simulation analysis were carried out for different materials. The results indicate that the reflection of specular reflection is stronger in the range of small angle, and the reflection of diffuse reflection targets can be detected within a larger angular range. The test results directly reflect the imaging performance, which can reflect the BRDF characteristics of different target materials. The results provide data and theoretical basis for the design of the laser active detection system of the space target and the performance analysis of the system.