Abstract: The estuarine delta is a complex system formed by the coupled interactions of hydrology, geomorphology, and ecology. The evolution of the estuarine delta is characterized by strong spatiotemporal fluctuations, high sensitivity to disturbances, significant edge effects, and high environmental heterogeneity, making it a typical unstable region. From the perspectives of the evolution process of hydrology-geomorphology-ecology system, the coupling relationships, multidimensional regulation theories and techniques of the Yellow River Delta, this study elucidates the adaptive adjustment and state characteristics of the hydrology-geomorphology-ecology subsystem under multiple pressures. This study also summarizes the mutual feedback relationship between hydrological conditions and the evolution of the estuarine geomorphology-ecology system. In addition, this study establishes a multidimensional collaborative research framework for water and sediment allocation and proposes a multidimensional regulation strategy based on optimized water and sediment allocation. In response to current research gaps, key directions for future research are proposed, including the construction of continuous monitoring platforms, the building of whole-process models, the prediction of imbalance risks, and the study of multidimensional regulation theories and techniques. These efforts aim to provide scientific support for optimizing the use of limited water and sediment resources to maintain the stability of the estuarine system.