Abstract: The ultraviolet/chlorine (UV/Cl) advanced oxidation process (AOP) is an emerging water treatment technology that combines ultraviolet irradiation with free chlorine to generate reactive species such as HO^•、Cl^•、Cl₂^•−. This process demonstrates high efficiency in degrading various micropollutants, including antibiotics, pharmaceuticals, and endocrine-disrupting compounds, while simultaneously offering disinfection capabilities. This review summarizes the radical generation mechanisms, oxidation properties, and degradation pathways of contaminants in the UV/Cl system. It also discusses the influence of key factors such as pH, chlorine dosage, and water matrix components, as well as the formation and control of disinfection byproducts. With its broad-spectrum oxidation capacity, high efficiency, and synergistic action, the UV/Cl process holds significant potential for advanced water treatment in both drinking water and wastewater applications.