Abstract: The design of controllable temperature irradiation facility for on-line measurement of electrical performance of electromagnetic coils in swimming pool light water reactor (swimming pool reactor) was introduced. In the design process, MCNP program was used to carry out neutronics physical calculation, the structure size and material composition of the swimming pool reactor and coil skeleton were simulated in fine full scale, and the heating power and neutron fluence rate of the irradiation facility were obtained. Through preliminary estimation, the temperature of the coil in the irradiation facility during the operation of the reactor was obtained by numerical simulation using ANSYS CFX, and the method of temperature control was proposed. The irradiation facility was made of aluminium, and the verticality test, pressure test and leak detection test were carried out. Insulation design was taken into account to insulate the irradiation facility from the swimming pool reactor. Armored thermocouples were embedded in the coil to monitor the coil temperature in real time. The electromagnetic coil was irradiated in the swimming pool reactor. The results show that the irradiation facility can meet the requirements of the electromagnetic coil irradiation test in the swimming pool reactor channel, and can control the temperature of the electromagnetic coil in real time.