A technique has been developed to characterize the doping concentration distribution of inertial confinement fusion capsules based on a method combining absorption retrieval, computerized tomography, and a gradient doping absorption model. The doping concentration distribution in a reconstructed slice of Si-doped capsules was obtained using this method and on average is in good agreement with contact radiography by comparison experiments. The established technique has been used to obtain a three-dimensional point cloud of the doping concentration distribution by reconstructing all of the slices for the doping capsules. Uncertainty of the doping concentration was analyzed, and the expanded uncertainty is approximately 0.1 at. % (K = 2).