Carbon peaking and carbon neutrality is a huge challenge for traditional industries, so how to achieve synergistic efficiency in the reduction of pollution and carbon emission is becoming increasingly important. Microalgae can fix CO2 through photosynthesis, and it can also use waste gas and wastewater as nutrient sources to achieve growth, reducing pollutants while producing value-added biomass, which provides a new biotechnology route that is expected to help realize the carbon peaking and carbon neutrality goals. Based on the development status of microalgae carbon fixation and emission reduction technology, the paper discusses the mechanism of microalgae photosynthesis for fixing CO2, reviews the key factors and strengthening strategies such as inorganic carbon source, mass transfer, light source, temperature and pH that affect the efficiency of microalgae carbon fixation, deeply analyzes the dissolution, transmission? absorption? utilization and transformation mechanism of NOx and SOx in the microalgae culture system, systematically explores the methods and technology roaclmap of microalgae emission reduction of flue gas pollutants, and further summarizes the effect mechanism and potential of microalgae in sewage treatment and heavy metal treatment. Moreover, relevant reviews are conducted on the high-value conversion and industrial application of microalgae biomass. Finally, the challenges to current practice and future prospects faced by microalgae biotechnology are discussed, providing a reference for the exploration of technical approaches, development and applications, and engineering practices regarding collaborative pollution reduction and carbon reduction in pursuit of carbon neutrality. © 2024 Editorial Office of Acta Petrolei Sinica. All rights reserved.