The use of data of National Radiometric Standard took place in the WMO International Pyrheliometer Comparisons IPC-XI to evaluate the expended uncertainty of the comparison result between National Radiometric Standards(NRS)and the World Radiometric Reference(WRR)in Davos/World Radiometric Center. The result of expended uncertainty is 0.17%, which meets the requirements of the World Meteorological Organization (WMO) and has reached the world advanced level. In this paper, the method can be used as a reference and basis for evaluating the uncertainty of the comparison results of the Provincial solar radiation standard.