In order to study the relationship between the zooplankton community structure and the water environmental factors in the Moguhu Reservoir, we conducted three detailed investigations in April, July and November in 2016. We used the Margalef ′s richness index and redundancy analysis method to analyze the density, biomass and dominance of zooplankton in different months, as well as the relationship between the structure of zooplankton community and the environment, the degree of nutrition of the reservoir. A total of 36 species of zooplankton were detected, including 7 species of protozoa, 18 species of rotifer, 4 species of Cladocera, and 7 species of Copepods (Table 4). The community structure of zooplankton was mainly dominated by rotifers and copepods in the three sampling. The average annual density of zooplankton was 3 574 ind/L, and the density variation range of each sampling point was 284﹣5 162 ind/L (Fig. 2); The annual biomass was 3.79 mg/L, and the range of biomass of each sampling point was 0.84﹣6.56 mg/L (Fig. 3). The density and biomass of zooplankton in three samplings reached the maximum in July, and the differences in density and biomass were significant at different periods (P < 0.01). Three surveys identified eight dominant zooplankton species (degree of dominance ≥ 0.2), including 5 species of rotifer, 2 species of Cladocera and 1 species of copepods (Table 5). The zooplankton community composition and environmental factors in the Mushroom Lake Reservoir were subjected to trend correspondence analysis (DCA) (Fig. 4), and the first axis gradient was tested, because the gradient of the three periods was less than 3, so the final selection redundancy analysis (RDA) was selected for the constrained sequencing. The test results show that water temperature, nitrate nitrogen, dissolved oxygen, pH, and chemical oxygen demand can affect the zooplankton community structure in April (wet season); Water temperature, dissolved oxygen, total phosphorus, chemical oxygen demand, and can affect the structure of zooplankton community in July (normal season). Water temperature, pH, and dissolved oxygen can affect zooplankton community structure in November (dry season). Water temperature and dissolved oxygen were the environmental factors that mainly affected the zooplankton community structure in three different periods.