In order to measure the concentrated solar radiation flux distribution of curved surface absorbers, based on segmented-jointed approaches, a measurement method for the solar flux density distribution on the curved surfaces is proposed according to the characteristics of the surface radiation transfer. By dividing and extracting the hemispherical shell, a hollow water-cooled strip spherical arc Lambertian target is designed and processed. Using image space coordinate transformation and surface radiation transfer calculation, the entire spherical shell surface is obtained by splicing multiple sub-images. The measurement method is experimentally verified on an indoor solar simulator using a CCD camera to assemble a test system. The results show that the uncertainty of this method is 5.12%. The distribution of solar flux density along the circumferential and zenith angles of the hemispherical surface is uneven, and the peak energy flux density appears at the outer edge of the surface vertex, which is significantly different from the focal plane energy flux density distribution.