A method of treatment of radioactive wastewater. The method includes: allowing radioactive wastewater to undergo reverse osmosis treatment and continuous electrodeionization treatment in sequence. The continuous electrodeionization treatment is carried out in a continuous electrodeionization unit including a continuous electrodeionization membrane stack including a dilute chamber and a concentrate chamber. The dilute chamber is filled with between 30 and 60 vol. % of a first strong-acid cation exchange resin, between 40 and 60 vol. % of a first strong-base anion exchange resin, and between 0 and 30 vol. % of a weak-base anion exchange resin. The concentrate chamber is filled with between 20 and 50 vol. % of a second strong-acid cation exchange resin, and the rest is a second strong-base anion exchange resin.