In the context of ‘dual-carbon’ goal, the traditional process with heterotrophic denitrification as the technological core cannot meet the demand for low-carbon nitrogen removal. Sulfur-driven autotrophic denitrification (SDAD) has received widespread attention in the field of biological nitrogen removal due to the advantages of efficient nitrogen removal and simultaneous carbon reduction. Based on existing research both domestically and internationally, this paper systematically reviews the latest advancements in SDAD and its derivative technologies, with a focus on process efficiency, microbial metabolism mechanisms, Progress in greenhouse gas (N2
O) emission reduction mechanisms and engineering applications, and obtained the following conclusions: (1) The SDAD system consists of three types of microorganisms, Autotrophic Sulfur-oxidizing Nitrate-Reducing Bacteria (a-soNRB), Heterotrophic Sulfur-oxidizing Nitrate- Reducing Bacteria (h-soNRB), Heterotrophic Sulfur-oxidizing Nitrate- Reducing Bacteria (h-soNRB), and Sulfur Disproportionating Bacteria (SDB) interacted with each other to complete nitrogen removal. At low sulfide concentration (S2-
concentration 6.25 mmol/L), a-soNRB was the main functional bacterium. When the sulfide concentration increased, a-soNRB and h-soNRB interacted with each other in the system to ensure high process efficiency. (2) In terms of carbon reduction, different operating conditions mainly affect the N2
O reductase (Nos) activity to control N2
O production. Overall, SDAD plays an important role in the treatment of sulfur-containing wastewater and other composite pollutants in practical applications, and the emission of N2
O from SDAD under the same operating conditions is only 1/5 of that of the traditional heterotrophic denitrification process, which provides an effective solution for the improvement of the traditional biological denitrification process by providing a high efficiency of denitrification and a significant reduction of carbon emissions at the same time. (3) In terms of engineering applications, the coupling of SDAD with heterotrophic denitrification, anaerobic ammonia oxidation and other processes further expands its application field, giving full play to the radiation effect of the advantages of SDAD's low-carbon denitrification. Finally, it concludes with an outlook on the challenges faced by wastewater denitrification processes with SDAD as the core technology and encourages future research to develop multi-pathway process combinations for different scenarios based on feasibility and environmental friendliness(e.g. Anaerobic ammonia oxidation, Partial denitrification, Sulfur-driven autotrophic denitrification and coupling with nitrate/nitrite-dependent anaerobic methane oxidation), as well as to further optimize model-based carbon reduction strategies and predict the behavior of novel pollutants, with a view to providing theoretical basis for advancing the field of low-carbon denitrification of wastewater for further development.