In response to the frequent occurrence of extreme flood and drought events, which have led to the continuous degradation of the habitat of the Vallisneria spp. in dish-shaped lakes of Poyang Lake, a remote sensing-terrain-water depth potential habitat suitability assessment method was constructed based on hydrological, remote sensing, terrain, and monitoring data of the Vallisneria spp. The impact of extreme flood and drought events on the habitat of the Vallisneria spp. was quantified. The results show that dish-shaped lakes exhibit significant interannual and seasonal fluctuations in water area, with extreme flood and drought events producing maxima and minima of 53.08 km² and 1.80 km², and mean expansion and contraction rates of 0.41 km²/d and 0.34 km²/d. In 2020, winter buds were detected only in Shahu Lake