Abstract: To investigate the environmental characteristics of Euglena blooms in aquaculture ponds in the Kaijiang area of Sichuan province, water quality monitoring was conducted over one culturing cycle from April to September 2022 in three ponds with Euglena blooms and three ponds without Euglena blooms at Kaijiang Minsheng Fisheries Development Co., Ltd. The results showed that the occurrence of Euglena algae blooms led to lower dissolved oxygen, conductivity and total dissolved solids in the cultured ponds compared to the ponds without blooms. The low total dissolved solids had a certain impact on the growth of crustaceans, resulting in smaller size and lower survival rates. The water temperature and pH in the aquaculture ponds were suitable for Euglena blooms. The total nitrogen and total phosphorus were suitable for Euglena blooms, and nitrogen was the limiting factor of Euglena blooms in this area. During the experiment, the permanganate index severely exceeded the standard for Class III waters, and the Euglena algae blooms exacerbated the accumulation of the permanganate index. The death of Euglena released absorbed nutrients, further deteriorating the water quality. Reasonable planting of aquatic plants such as Elodea nuttallii and Hydrilla verticillata during the cultivation period could effectively inhibit the outbreak of Euglena bloom.