Based on field sampling surveys of aquatic plant species, population status and spatial distribution, the minimum ecological water level of Xuanwu Lake was determined using the lake morphology analysis method and the biological lowest space demand method. The water level regulation scheme of aquatic plants at different growth stages was formulated considering the water level demand of aquatic plants. The results show that the species of aquatic plants in Xuanwu Lake are rich, but the coverage is not high, which is 13.2%. The coverage of submerged plants is very low with a value of 2.1%. The minimum ecological water level of Xuanwu Lake is 9.6 m.The recommended water level during the germination stage is 9.9 m, which can reach the goal of 30% coverage of aquatic vegetation and is beneficial to the germination of aquatic plants, especially submerged plants. The recommended water level in summer is 9.8 m, which can guarantee flood control security, control overgrown emergent plants such as lotus flowers, and promote the growth and recovery of the overall aquatic plants in the lake.