Affected by global climate change and anthropogenic activities, the degree of saltwater intrusion in China tidal river sections has been intensifying, posing a serious threat to the water-using safety and ecological stability in estuarine areas. The need for saltwater intrusion control is becoming increasingly urgent. Based on the finite volume ocean model, a hydrodynamic salinity numerical model of the estuary area was constructed with the downstream reaches of the Min River as the research region. The model simulated the saltwater intrusion scenario under extreme drought events and explored the influence regulation of upstream reservoir scheduling on saltwater intrusion. The results demonstrate that increasing the discharge flow from upstream reservoirs can significantly reduce the degree of saltwater intrusion. Under the ex-tremely drought conditions during the 2022 dry season, an increase of 240% in reservoir discharge could effectively push the saltwater intrusion boundary back to the confluence of the North Channel and the South Channel. When upstream reservoirs discharge was increased at varying gradients, the morphological differences between the North Channel and the South Channel led to uneven flow distribution, thereby differentially affecting saltwater retreat in the two channels. At an 80% increase in upstream discharge, the North Channel exhibited the maximum retreat of the saltwater intrusion front, beyond which the retreat rate diminished with further flow increases. In contrast, the South Channel showed a propor-tional retreat of the saltwater intrusion front with each incremental doubling of upstream discharge. In addition, when the upstream flow increased in a gradient manner, the longitudinal salinity along the lower reach was significantly reduced, with the largest decrease when the flow increased by 80%, and then the decrease became smaller. This study provides guidance and scientific basis for the formulation and implementation of prevention strategies for saltwater intrusion events in tidal rivers.