Abstract: Extreme meteorological and hydrological events frequently occur in the changing environment. The Yangtze River and Yellow River are facing the risk of simultaneous dry events. This paper analyzes the practical problems encountered in the Yangtze River basin and Yellow River basin following the construction of the national water network in order to ensure water resources security in the Yellow River basin when these two rivers experience simultaneous dry events. Urgent key scientific problems that need to be addressed include simultaneous dry events of large-scale basins in the changing environment, water crisis formation, interbasin water transfer potential, water network formation and the water transfer mechanism of multi-line projects, water resources security assurance during extreme dry events. An overall research framework for addressing extreme dry events in the Yellow River basin under the layout of the water network is proposed. Key research directions are analyzed from five aspects, namely, occurrence patterns and spatial variation mechanisms of simultaneous dry events in the Yangtze River and the Yellow River; quantitative assessment of multi-link transmission and compound impact of water crisis risk; interbasin water transfer potential in extreme dry events, interbasin water allocation and refined regulation of multi-line water transfer projects; and improvement of the resilience of thebasin water resource system during extreme dry events.