The partial denitrification (NO₃^--N→NO₂^--N), a promising way for nitrate wastewater treatment, could combine with ANAMMOX technology to achieve nitrogen removal with low concentration of carbon source and poor energy. Three different domestication pattern, R1 (SBR under anoxic condition), R2 (SBR under anoxia-aerobic alternating condition) and R3 (SBR under anoxic condition with low-intensity aeration), were conducted using glucose as electron donor to find out the rule of nitrite accumulation in denitrification process. These three reactors achieved steady nitrite accumulation after 120-days run, and the sludge were taken, respectively, to explore the denitrification pattern of these three acclimatizing ways. The findings revealed that, compared with R1, the R2 and R3 sludge could better achieve partial denitrification due to the involving of dissolved oxygen. And R3 was the best way. The microbial community structure of R1, R2 and R3 sludges on the 109th day were analyzed and compared by high throughput sequencing. The results showed that the dominant bacteria were Candidatus Saccharibacteria in both R2 and R3 reactor, which were with the participation of dissolved oxygen, and the relative abundance was 45.44% and 34.96%, respectively. This was the first time that the Candidatus Saccharibacteria was reported as the dominant bacteria in the denitrifying sludge. Besides, the microbial diversity of R1reactor was much larger than that of R2 and R3, which indicated that the denitrifying bacteria in R2 and R3 reactors were more exclusive. The batch experiments showed that the initial pH had a significant effect on the accumulation of nitrite. The higher the pH indicated the higher accumulation rate of nitrite.