Abstract: During the Typhoon "Co-may" in 2025, the water level of Suzhou River exceeded the historical maximum, which posed a severe challenge to the flood control safety in Shanghai City.The precipitation along the Suzhou River during Typhoon "Co-may" and the cause of the super historical high water level of Suzhou River were intruduced, which was compared with the water situation of Suzhou River during Typhoon "Kong-rey" in 2024.The solution was put forward, and the effect of the solution was simulated by the hydrological hydrodynamic model.The results showed that the main reason for the super high water level of Suzhou River during Typhoon "Co-may" was that the storage capacity of the river channel increased sharply in a short time.Specifically, the extreme heavy precipitation brought by the Typhoon led to the rapid collection of waterlogging from both sides of the water resources area to Suzhou River, and at the same time, the discharge capacity of Suzhou River′s waterlogging was severely limited by the bottom water in the upper reaches and the top of the high tide in the outer river.The double adverse factors of "fast inflow and slow discharge" were super-imposed, causing the water level to rise rapidly.Compared with the 2024 Typhoon "Kong-rey", the intensity of Typhoon "Co-may" was strong, the rainfall was concentrated, and the water storage and drainage of Suzhou River in the water conservancy area and polder area were significantly increased.According to the model inversion analysis, the maximum water level of all stations along Suzhou River could be reduced by about 0.3 m if the discharge limit scheme was implemented according to the current working conditions.If the Huangpu River estuary gate and Suzhou River estuary pump were planned, the highest water level along the Suzhou River could be reduced by 0.19 ~ 0.48 m, which could significantly enhance the flood control and drainage capacity of Suzhou River.