The utility model discloses a reactor of radioactive wastewater is handled to million multikilowatt nuclear power stations. The lower part in reactor chamber is distinguished for the adsorption reaction, and the upper portion in reactor chamber is the disengagement zone, be provided with the water inlet and the agitating unit of radioactive wastewater in the adsorption reaction district, be provided with in the disengagement zone and be detained the adsorbent at reactor's intercepting device, intercepting device's top is provided with the delivery port of handling back waste water. The utility model discloses changing current fixed bed absorption into thermopnore and adsorbing, the adsorbent that can select powder or tiny particle improves the adsorbent through the stirring and fully contacts with the radioactive wastewater in order to increase specific surface in the radioactive wastewater, can carry out the preliminary treatment to a large amount of radioactive wastewaters fast.