The method of on-board calibration based on sun-diffuse panel panel plus radiometer for stability monitoring can improve the level of quantification of remote sensing data, and the BRDF calibration accuracy of diffuse panel is the key of high-precision on-board calibration, and the BRDF absolute measurement can realize high-precision calibration of the diffuse panel. In order to solve the key technology of high-precision BRDF absolute measurement, we design a high-brightness, high-stability and high-uniformity integrating sphere as the lamp source; using a monochromator and a single detector to detect the incident and reflected radiance signals with large dynamic range accurately, moreover using a lock-in amplifier to amplify and acquire the signals; using high-precision six-axis robot and hollow rotary indexing table orientate sample diffuse panel with three-dimensional rotation and translation and lamp source with one-dimensional rotation separately to construct BRDF absolute measuring geometry with high-precision, non-blocking and speediness. The device can realize omnidirectional BRDF measurements except for that out of plane, and measurable angle range is: azimuthal angle is 0°~360°, and zenith angle is 0°~75°. Currently measurable spectral range is 250~1700 nm. The uncertainty degree of this device can be less than 1%.