Coal plays an important role in meeting global energy demand, and is also an important part of China′s primary energy structure.With the transformation of China′s economy to a high-quality development stage, the construction of ecological civilization has entereda critical period to promote the coordinated development of pollution reduction, carbon reduction and efficiency improvement, promotethe comprehensive green transformation of economic and social development, and realize the improvement of the quality of the ecologicalenvironment. Clean and efficient use of coal has become the focus of national work. Coal gasification wastewater is the main wastestream generated by the low-temperature/ medium-temperature gasification units. It is characterized by high content of phenol and ammonia, and contains various toxic and difficult - to - degrade organic and inorganic pollutants. It is a typical industrial wastewater withhigh concentration and biological resistance, which has obvious negative impacts on the environment. The reverse distribution of water resources and coal resources in China makes wastewater treatment and recycling not only a response to energy conservation and emission reduction policies but also an important measure for optimizing the allocation of water and coal resources. At present, various technologieshave been applied to the treatment of coal gasification wastewater. After balancing factors such as treatment effect and economy, a consensus has been reached that the physical-chemical and biological treatment processes combining anaerobic and aerobic processes should beadopted. The technical route of this treatment is mainly composed of pretreatment, biological treatment and advanced treatment, and thetreated wastewater can meet national sewage discharge standards. This article introduces the relevant technologies, treatment effectiveness,and advantages and disadvantages of the pretreatment, biological treatment, and advanced treatment of coal gasification wastewater. It analyzes the technical bottlenecks in production, and introduces other new treatment processes, such as freezing concentration, steam-waterintegration with near zero emission and microbial fuel cell methods. From the analysis of relevant literature, most of the researchon coal gasification wastewater treatment still focuses on specific methods, while ignoring the comprehensive engineering system of thetreatment process. It is necessary to focus on optimizing the integration of physical-chemical, advanced oxidation, and biological treatmenttechnologies, improving treatment efficiency, reducing construction and operation costs, and strengthening the development of new processes. Better combination of the coal gasification wastewater treatment process and gasification process can improve the potential for water reuse and reduce energy consumption and pollutant production. Finally, it is important to pay attention to the resource utilization of coal gasification wastewater, explore its potential resource value, develop utilization methods, and truly tap into the resource potential of gasification wastewater, thus turning waste into treasure.