Abstract: Membrane distillation can be used for deep purification of radioactive wastewater, but the traditional direct contact membrane distillation technology has the disadvantages of low membrane flux and high energy consumption, the industrial use is limited. In order to overcome the insufficient of direct contact membrane distillation, develop non-contact membrane distillation, it is necessary to establish the low temperature evaporation technology of wastewater. Based on the self-made low temperature evaporation device, the evaporation characteristics and capacity of the device were studied by means of experimental measurement and theoretical simulation. Under the same conditions, the experimental results of the performance of the self-made low-temperature evaporation device are consistent with the theoretical calculations. It is theoretically calculated that the maximum evaporation capacity of the device is 80.6 kg/h in the operating range, and the maximum evaporation capacity can reach 1 143 kg/h when the size of the low-temperature evaporation device is enlarged to 1 m tower diameter and 3 m packing height; the ion removal rate reflected by the conductivity of the condensate water from the device reaches 89.5%. The low-temperature evaporation device can provide stable and sufficient wet air to be treated for the subsequent membrane distillation device, which lays the foundation for the development of non-contact membrane distillation technology.