In this paper, the composition and working mode of the on-board calibration component on the visible and near infrared band of GF-5 visible and infrared multispectral imager (VIMI) is introduced. The attenuation of on-board 12-time solar diffuser (SD) bidirectional reflection distribution function (BRDF) on the satellite after VIMI launch is analyzed. Comparing the long-term solar data observed by SD reflectance degradation monitor (SDRDM) shows that the attenuation degree of different monitoring band detectors is different. Among them, the 900 nm monitoring band silicon detector has the largest attenuation, about 4.3%. When the incident angle is close to the observation azimuth, the attenuation factor (H factor) of SD BRDF changes little. According to the physical model of the H factor, the measurement uncertainty of actual monitoring by SDRDM is less than 0.86%, which meets the index requirement of less than 1.5%, and the radiance uncertainty of the output spectrum of the calibration component on the VIMI satellite is less than 3.4% during the lifetime.