As existing Bidirectional Reflectance Distribution Function (BRDF) measuring device is three-axis equipment, and it can not implement the whole angle BRDF measurement in a 2π space on the sample surface. Therefore, a new device was built for BRDF measurement in this paper. A six-axis robot was used as object positioning mechanism to implement three-dimensional rotating for changing the normal direction of the object at the measuring point, and a turntable was used as the detection positioning mechanism to implement one-dimensional rotating for changing the orientation of detector around the measuring point, so that four-dimensional rotation was constructed to form the four-angle geometry of BRDF measurement. The measuring geometry of incident and reflected beams of the device shows its azimuthal angle to be 0—360°, zenith angle to be 0—70°, and the spectral range is 350—2 500 nm.The process of BRDF measurement is controlled by software, and the BRDF measuring geometry is constructed with high-precision, non-blocking, fully automation and speediness. With an average measurement of about 8 s, the device completes the geometry of construction and spectral scanning, transmission, display and the storage. The uncertainty budget of the device is less than 2.5%(k=2).