The joint operation of Xiaolangdi Reservoir with Sanmenxia Reservoir and tributary reservoirs after the completion of Xiaolangdi Reservoir marks the basic completion of the downstream flood control and disaster reduction project system. However, for the Yellow River beach area, which has always been emphasized as the space for flood detention and sediment deposition, the reservoir flood control operation has set the goal of ensuring that the beach area is not filled with water for many years. Taking the autumn flood in recent four years, including 2021, as an example, this paper showed that it was more difficult to block and stagger the peak of the reservoir after the superposition of a variety of adverse factors, especially when the inflow of trunk tributaries was encountered. In order to solve this problem, it was considered that under the specific restriction of Huayuankou flow. Sanmenxia Reservoir should be allowed to stop the flood, transition to the non flood season pool level in advance, help Xiaolangdi Reservoir reserve the storage capacity under the maximum allowable water level, and skillfully stagger the flood discharge. When necessary, the temporary storage water level of Sammenxia Reservoir could break through to reduce the safe ty risk of high water level of Xiaolangdi dam. In addition, under the current situation that the amount of sediment entering the reservoir de creased greatly. The operation mode of Sanmenxia Reservoir should be adjusted and improved, strive to make this pearl of the Yellow River shine again, improve the downstream flood control engineering system, give play to the role of optimizing the allocation of water resources, and provide safety guarantee for downstream flood control, disaster reduction and high-quality development. [ABSTRACT FROM AUTHOR]