Radioactive ¹²⁵I seeds implantation has been widely used in the comprehensive treatment of various malignant tumors. In recent years, the amount of radioactive ¹²⁵I seeds implantation therapy in nuclear medicine has increased year by year, which has become an important project of radionuclide therapy. In order to promote and standardize the treatment of radioactive ¹²⁵I seeds implantation in nuclear medicine, strengthen quality control, carry out big data research and multidisciplinary cooperation, and standardize clinical treatment, the Therapeutic Group of Chinese Society of Nuclear Medicine has organized some experts of the Working Committee of Therapeutic Group Radioactive Particle Interventional Therapy to formulate the expert consensus, which draws lessons from the current guidelines and latest researches at home and abroad, as well as relevant laws and regulations, combined with the clinical situation of our country. The consensus includes three parts: general requirements, quality management control, and protection requirements. Radioactive ¹²⁵I seed implantation therapy, as a radioactive interventional therapy, has the dual characteristics of radionuclide intervention clinical technology and radionuclide management. The consensus standardizes in two aspects of technical quality control and radionuclide management, and fundamentally solves the problems in the field of seed implantation therapy, thus improving the therapeutic effect and promoting the smooth development of radionuclide ¹²⁵I seed implantation therapy.