Sulfur autotrophic denitrification (SAD) has become one of the hotspots in nitrogen removal technology during wastewater treatment because of its characteristic green and low-carbon technology for nitrogen removal from sewage, which has the advantages of low cost, low sludge yield, and no need for organic carbon sources. In this paper, the research progress on SAD of carrier compositions and synthesis method of composite sulfur source filler. The structure and applicable conditions of SAD packed bed reactor and fluidized bed reactor were summarized. The research progress of SAD coupled with electrochemical, heterotrophic denitrification, and anammox processes were reviewed. The advantages and disadvantages of SAD and the nitrogen removal characteristics of the three described. In addition, the typical SAD microorganisms were summarized, and the denitrification characteristics and growth conditions of Thiobacillus and Sulfurimonas in SAD process were described. Finally, the prospects of further development of low-temperature SAD technology, high treatment load reactor design, and optimization of short process technology are presented. This review aims to provide references for researchers and engineers of wastewater denitrification.