Abstract: In this paper the evaporator system of the radioactive waste disposal center was introduced in brief firstly.Considering the problems of the traditional process such as it is unable to meet the handling capacity for the radioactive wastewater of the newly connected nuclear facilities,the design for the key equipments of the evaporation process and the system in the aspect of secondary steam demisting is optimized.The mist entrainment of the evaporator primary gravity separation segment and the built-in bubble column is reduced,the purified water in the system is used to wash the secondary steam,and the mesh demister is combined to further separate the entrainment.The purifier with high efficiency coalescing filter element is used to purify in high precision.The proposed system can improve the purification and the decontamination factor of radioactive wastewater based on the radioactive waste minimization principle by verifying,and the whole evaporated system and equipments was simplified.