Abstract: Dietary ecology is fundamental to understanding wildlife-habitat interactions, serving as a cornerstone for assessing environmental carrying capacity, habitat quality, habitat selection behavior, trophic structure, and interspecific competition/mutualism in community ecology. It remains a pivotal focus in endangered species conservation and biodiversity management. Ornithologists have long recognized the significance of dietary studies; for waterbirds-key indicator taxa in wetland ecosystems-dietary data elucidate species-environment energy/material linkages and critically inform ex situ conservation strategies and captive breeding optimization, particularly for threatened species. Methodologically, waterbird dietary research employs diverse approaches. Traditional techniques (direct observation, gizzard/crop content analysis, fecal microscopy) historically dominated the field. Technological advances now highlight DNA metabarcoding for its high taxonomic resolution, though constrained by sample DNA degradation and cost-intensive procedures. Conversely, stable isotope analysis demonstrates broader utility: beyond resolving dietary composition, it enables migration tracking, quantification of seasonal dietary dynamics, trophic-level mapping, and evidence-based population management and wetland restoration. Amid accelerating climate change and pervasive habitat loss/fragmentation, the scope of waterbird dietary research now transcends conventional boundaries. Objectives have expanded from basic diet characterization to multidimensional investigations of spatiotemporal foraging patterns, habitat restoration efficacy, and migratory ecology. Methodologically, interdisciplinary integration (ecology, genetics, physiology, molecular biology) drives advances in: climate-driven dietary adaptation mechanisms, gut microbiota-diet interactions, paleo-dietary evolution from fossil evidence, migration-resource phenology alignment, precision wetland rehabilitation. High-throughput, information-rich analytical tools (e.g., DNA metabarcoding, stable isotopes) provide unprecedented resolution for quantifying dietary seasonality, migration-stage shifts, and species-distribution-environment relationships. With persistent technological advancements and scientific inquiry, waterbird dietary ecology will increasingly underpin biodiversity conservation, ecosystem governance, and global change mitigation.