Abstract: Lung cancer is the most common primary malignant tumor. Because most sufferers have already been in later stage in their first diagnosis, the lump body infringing upon the important organs often influences the excision of tumor. ¹²⁵I seeds permanent implantation is a new method for tumor brachytherapy, which contributes to kill the tumor completely, ensures the normal physiological functions of organs, reduces tissue injuries and treatment of complications, and raises the survival rate of sufferers. The rapid promotion of this technique is also followed by radiation risks in the treatment. Currently, the researches of ¹²⁵I seeds implantation is limited to the aspects of treatment means and effects, with no detailed study in intraoperative usage, disinfection and protection. Although a satisfactory curative effect is the key in the treatment, the studies in protection principles, means and technological upgradation are also too important to be ignored.