Abstract: According to the demand of risk assessment of a uranium tailing in China, the mathematical model of radionuclide migration in the vadose zone and saturation zone was established according to the hydrogeological conditions of the specific site. On the basis of theoretical model, the migration equation was solved based on the generalized integral transform technique, and the migration rules of ²³⁸U, ²³⁴U, ²³⁰Th, ²²⁶Ra and ²¹⁰Pb in the uranium tailing were analyzed in four scenarios. The results show that the generalized integral transform technique for evaluating relatively complex underground pollutant migration issues is very effective, and especially for small contaminant concentration and long time scale, the result is very accurate. The thicker vadose zone not only can reduce the rate of nuclide migration in saturation at the lowest extent, but also the concentration is low. The stronger adsorption performance of the medium is, the greater the role of the retardation of radionuclide migration is.