Abstract: Radioactive iodine isotopes, particularly the long-lived ¹²⁹I with its half-life of 15.7 million years and the highly radiotoxic, short-lived ¹³¹I (half-life 8.02 days), generated ubiquitously during nuclear fuel cycling and nuclear technology application, pose a serious threat to ecological environment and human health due to bioaccumulation in the thyroid gland. At present, most technological research and development predominantly focuse on the capture and immobilization of volatile gaseous iodine species (I₂ and CH₃I) using solid sorbent like silver-exchanged zeolites or covalent organic frameworks, while the efficient treatment of dissolved iodine anions(I^–, \mathrmIO_3^- ) in complex low-level radioactive wastewater has not received sufficient attention. These radioactive iodine-containing wastewater is characterized by low concentrations, and the presence of high concentrations of competing anions like \mathrmNO_3^- or \mathrmSO_4^2- . They may enter aquatic environments through accidental leaks during spent fuel reprocessing, nuclear accidents, or radiopharmaceutical production and use. Notably, with the rapid global development of nuclear medicine, especially thyroid cancer therapies and diagnostics, the demand for treating radioactive medical wastewater containing significant quantities of ¹³¹I has shown exponential growth. This review summarizes the latest advances in treatment technologies of dissolved iodine anions(I^–) in complex low-level radioactive wastewater, such as chemical precipitation, adsorption/ion exchange, membrane separation, biological treatment, photocatalytic oxidation, and electrochemical methods. The mechanism and key performance parameters(including adsorption capacity, kinetics, selectivity, pH dependence, and regenerability) of each approach were systematically analyzed, and the advantages, disadvantages and applicable scenarios of each technology were compared and summarized. Among them, chemical precipitation employs agents such as Ag⁺ or Cu⁺ ions to form insoluble AgI or CuI compounds, but it is often disturbed by Cl^– and Br^– and generates secondary sludge, which requires complex disposal procedures. The materials utilized in adsorption or ion exchange include layered double hydroxides(LDHs), anion exchange resins, quaternary ammonium-functionalized fibers, or silver-based ionic composites, and have the advantages of rapid kinetics and high selectivity. Membrane separation such as reverse osmosis(RO) and nanofiltration(NF) has limited applicability for volatile iodine. Finally, from the perspective of emphasizing scalability, robustness and cost-effectiveness, the work proposes a continuous column separation process, coupled with advanced solid adsorbent materials(e.g., optimized ion exchange materials) as a feasible approach for large-scale treatment of bulk radioactive iodine waste liquid. These materials have a high iodine affinity and excellent capture efficiency, which helps effectively reduce the volume of wastewater and generate a stable waste form for long-term disposal. The integrated strategy provides a feasible and efficient solution for the deployment of nuclear power plant wastewater treatment systems and centralized nuclear medical waste liquid treatment facilities.