In 2022, a severe drought event occurred in the Poyang Lake basin, which had a serious impact on the eco-environment of the Poyang Lake. In order to reveal the characteristics and main influencing factors of zooplankton community structure in the Poyang Lake during the extreme hydrological drought year, a comprehensive survey of zooplankton in the Poyang Lake was conducted in January (winter), April (spring), July (summer), and October (autumn) in 2022. A total of 70 species of zooplankton were identified (40 species of rotifers, 17 species of copepods, and 13 species of cladocerans), with the abundance and biomass ranging from 0 to 152.67 ind./L and 0 to 1.52 mg/L, respectively. Zooplankton community structure showed large temporal and spatial differences. Seasonally, the number of species was the highest in summer, and the abundance and biomass were the highest in summer and the lowest in autumn. The Shannon-Wiener diversity index and dominant species composition in the drought season were significantly different from those in the non-drought season. Spatially, the number of species, abundance and biomass in the southern lake zone were higher than those in the northern lake zone. The diversity index was the highest in the central lake zone and the lowest in the northern lake zone. In the extreme hydrological drought year, the number of species, abundance, and biomass were significantly lower than in the same seasons in previous years, but the spatial differences were small. The results of correlation analysis and redundancy analysis showed that there were significant differences in the main influencing factors of zooplankton community structure between the drought season and the non-drought season. The zooplankton community structure was mainly affected by combination of water temperature, water level, nitrate nitrogen, and ammonia nitrogen during the drought season. However, during the non-drought season, it was influenced mainly by chemical oxygen demand and water level. Overall, the extreme hydrological drought weakened the stability of zooplankton community structure in Poyang Lake compared with previous years. The study can provide essentially scientific and technical support for ecological protection of the Poyang Lake under extreme drought conditions.