Abstract: The pre-release capacity improvement project of Zhougongzhai-Jiaokou Cascade Reservoirs in Ningbo City improved the pre-release capacity of the two reservoirs effectively. During the defense process of 2212 typhoon "Meihua", the reservoir was optimized for pre-release scheduling, and the reservoir water level was dynamically adjusted quickly, which successfully prevented the over-standard flood (rainfall), and the pre-release capacity improvement project played an important role. By calculating and deducing the pre-release scheduling of Zhougongzhai Reservoir and Jiaokou Reservoir during Typhoon "Meihua", the flood control and disaster reduction effect of Zhougongzhai-Jiaokou Cascade Reservoir pre-discharge capacity improvement project and the benefits obtained were analyzed, which provided technical support for the pre-release scheduling of river basin cascade reservoir, and also provided reference for the function improvement and pre-release scheduling of similar cascade reservoirs (groups).