Abstract: From July 26 to 28, 2024, under the influence of the peripheral cloud systems of Super Typhoon "Gaemi" (No.2403), a severe torrential rainstorm occurred in the Xiangjiang River Basin. The rainstorm center was located in the upper reaches of the Leishui and Mishui rivers, along the mainstream of the Xiangjiang River from Hengyang to Zhuzhou, and in the Juanshui River tributary area. The maximum point rainfall for 3-hour, 6-hour, 12-hour, and 24-hour durations all broke historical records in Hunan Province. This triggered a major flood in the lower reaches of the Xiangjiang River’s mainstream and historical floods in multiple tributaries. By analyzing the spatiotemporal distribution of rainfall and flood evolution characteristics, and comparing them with the Typhoon Bilis-induced rainstorm flood in 2006, the results indicate that the cumulative rainfall in this event was 40% higher, with greater rainfall extremity, broader flood impact, and a peak flow reduction rate of 79% achieved by the Dongjiang Reservoir, demonstrating significant flood control benefits. The research results can provide scientific basis for rainstorm and flood prevention in Xiangjiang River Basin.