Water pollution is one of the prominent environmental problems at present. With the continuous emergence of various emerging water treatment technologies, cheap and efficient ecological treatment technologies have been developed rapidly, among which the application of microalgae biotechnology is extensively attentioned. The water treatment technology of microalgae was mainly classified according to the culture method of microalgae, including open pond culture system, closed photobioreactor culture system and immobilized culture system. Microalgae wastewater treatment technology can realize the simultaneous removal of nitrogen, phosphorus, refractory organics and heavy metals in sewage, and can be applied to different types of water treatment such as municipal sewage, aquaculture wastewater and industrial drainage. In the treatment process, the selection of algal species, the control of operating conditions and the selection of reactor will have a significant impact on the treatment effect. In this paper, the mechanism, efficiency and process characteristics of the removal of organics, nitrogen, phosphorus, heavy metals and other pollution factors by microalgae were reviewed. The progress and existing problems of microalgae wastewater treatment technology at home and abroad were summarized
