The scarcity of water resources and severe water pollution are two major challenges that the world is currently facing. With the development of social industry, water quality pollution is becoming increasingly serious, and people are paying more and more attention to the application of sewage treatment technology. Traditional treatment processes are no longer sufficient to meet the requirements of wastewater treatment, and ozone technology is gradually being recognized as an emerging technology more suitable for future use in the field of water treatment. The development of ozone technology has a history of more than 100 years. As early as the 19th century, people recognized the strong oxidizing effect of ozone and found that ozone has an oxidizing effect on substances such as wood, straw, starch, plant pigments, natural rubber, fat, animal and vegetable oils, and alcohol; In 1908, an experimental device for disinfecting tap water with ozone was built in Nice, France; Ozone oxidation method began to be used for urban and industrial wastewater treatment in the 1950s; In the 1970s, the combination of ozone oxidation and activated carbon treatment technologies became one of the main methods for removing chemical pollutants from sewage treatment and drinking water. Due to its strong oxidizing properties, ozone can oxidize various compounds and has the advantages of low consumption, fast reaction speed, and no sludge production. Therefore, it has been successfully applied in drinking water, industrial wastewater, and circulating cooling water treatment processes. Especially in the past two decades, it has been found that chlorine disinfection can produce trichloride (THMS), which has carcinogenic effects on the human body. Ozone disinfection is much more effective in killing live bacteria and viruses than chlorine disinfection. At the same time, it can also effectively remove inorganic substances such as color, odor, taste, iron, manganese, etc. in water, and can reduce UV absorption value, TOC, COD, and ammonia nitrogen. Therefore, ozone oxidation technology has been widely used in water treatment, and various more effective methods have been developed accordingly. Composite processing technology. The widespread and successful application of ozone technology in the field of water treatment is undoubtedly in the treatment of drinking water. At present, there are nearly two thousand ozone treatment plants, mainly distributed in Europe. The main functions of ozone in drinking water treatment include disinfection and sterilization, decolorization, deodorization, removal of iron and manganese, oxidation and decomposition of organic matter, and flocculation. In most water treatment plants, ozone is multifunctional. Years of research and practice have proven that ozone not only avoids the production of organic chlorides compared to traditional oxidants, but also has the advantages of improving filtration speed, reducing the number of filter tanks, promoting flocculation, reducing the number of flocculation tanks and flocculant dosage, prolonging filter usage time, reducing flushing water consumption, and improving water quality and sensation. In addition to treating drinking water, ozone is also widely used in municipal sewage treatment. With the continuous improvement of residents' requirements for quality of life, the impact of secondary treatment effluent from sewage treatment plants on urban water bodies has attracted more attention to health and safety issues. After secondary treatment, although the water quality of urban sewage has been improved, there are still a certain number of bacteria present. Therefore, disinfecting the effluent has become one of the important processes in sewage treatment. Ozone treatment method has been widely applied in the field of municipal sewage treatment due to its advantages of small footprint, high purification degree, no secondary pollution, and low production of floating slag and sludge. However, the overall process is still in its infancy, and various related technologies, supporting processes, equipment, and even standards are not yet perfect. It is a key development technology in the future. With the rapid development of China's economy and the strengthening of environmental protection efforts, the ozone industry will usher in a period of high-speed development. China is currently vigorously developing ozone wastewater treatment technology in order to provide better water quality and living standards for the people. At the same time, we believe that with the joint efforts of all sectors of society, there will be new breakthroughs and progress in the research of ozone in water treatment in China. We believe that ozone will be applied in a wider range of fields, bringing more health and cleanliness to our society.