The unified glare rating (UGR) is an important parameter to characterize the degree of glare and visual comfort of indoor lighting, which is widely used in indoor lighting detection and lighting design. At present, the tracing method of the glare tester in China only uses the brightness standard device to calibrate the brightness value, but there is no relevant calibration for the brightness distribution and geometric position information of the lighting source, resulting in the inaccuracy and inconsistency of the glare measurement results. In order to solve this problem, this paper developed a set of UGR calibration device, introduced the principle and structure of the device, and analyzed its uncertainty. The development of the device plays an important role in ensuring the accuracy and unity of the glare measurement results, effectively improving the lighting design quality and protecting the visual health.