The production of medical isotope125Ⅰ by continuous cycle irradiation can not only realize the cycle irradiation of the target material,but also the 125Ⅰ produced will be captured by the iodine adsorption device.The 125Ⅰ preparation process device system had been installed on site according to the site layout of Minjiang test reactor(MJTR).In this study,the process design concept,functional composition and research and development progress of the system are discussed in detail.Meanwhile,the air tightness,functionality and stability of the whole system device were debugged and verified by using the pressure maintaining of the loop and the simulation of the cycle irradiation process.The results show that the whole system device has good air tightness,and the functionality and stability of the equipment meet the technical design requirements.The research results lay a foundation for the follow-up thermal test research.