The invention discloses an irradiation intensity measuring scanner of a solar radiation simulator, which comprises a plurality of segments of longitudinal rails and a transverse bracket which longitudinally moves on the longitudinal rails through friction wheels and is vertical to the longitudinal rails, wherein the irradiation intensity measuring device moves longitudinally with the transverse bracket along the longitudinal rails and moves transversely with a platform of the measuring device along the transverse bracket. The irradiation intensity measuring scanner of the solar radiation simulator of the invention can be successfully applied in the measurement of the light distribution in an effective area of the solar radiation simulator in a combined way and performs the flat scanning measurement on the light distribution in the effective area. The transverse and longitudinal resolution of the scanning is 10 millimeters.