A phytoremediation method based on soil contaminated by uranium tailings comprises the steps for culturing pokeberry seedlings on a substrate containing uranium tailings, surviving, growing, harvesting and centrally processing. The method comprises the following steps of: (1) mixing soil contaminated by uranium tailings, surface oil of forest and pig manure according to a ratio to obtain a culture substrate; (2) adding sodium silicate in the culture substrate; (3) sterilizing seeds; and (4) potting. By adopting the comprehensive processing scheme combined with the pokeberry, the uranium tailings, the surface oil of forest, the pig manure and the sodium silicate, the method can solve the difficult problem that the environment can be endangered by heavy metal, uranium, which is released by uranium tailings under natural condition. The method has the advantages of convenient operation and management, high remedying efficiency, low cost, low environment risk, environment beautification, etc., and is suitable for processing solid-state uranium waste storage fields such as uranium mines, hydrometallurgy plants and waste ore and tailings reservoirs.