Abstract: As a novel biological nitrogen removal process, partial denitrification coupled with anammox (PD-A) process can save the cost of aeration and external carbon source, generate NO₂ ⁻ steadily and efficiently and have high removal efficiency of total nitrogen. Besides, PD-A process can reduce the emission of greenhouse gas N₂O. Existing researches on PD-A mostly focus on the simulated wastewater with single water quality conditions while the research on the real wastewater is still missing. The mechanism and characteristics of PD-A process were analyzed, the optimization strategy of PD-A process operation was proposed through comparing the optimal growth conditions of core functional bacteria, partial denitrification bacteria and anammox bacteria, in combination with the existing researches. Then the application cases of PD-A process in the real wastewater were analyzed. The results showed that optimizing COD/NO₃ ⁻, inoculating sludge with different structures and adding biofilm carriers were beneficial to the efficient and stable operation of the process. PD-A process could achieve higher nitrogen removal efficiency in the treatment of real domestic sewage, aquaculture wastewater and high nitrate wastewater, indicating that the treatment of real wastewater through PD-A process was feasible. Finally, the development trend of PD-A process was forecasted, the real wastewater should be treated, and the synergy mechanism of the core flora in the system and the mixed biological denitrification control method should be further studied to improve the stability of the process and the efficiency of synergistic removal of carbon and nitrogen.