Abstract: The Yellow River Delta National Nature Reserve (YRDNNR), located at the Yellow River estuary in Shandong Province, represents a typical example of China′s estuarine wetland ecosystems and plays a vital role in maintaining regional ecological stability and biodiversity. Vegetation cover fundamentally determines the integrity of newly formed wetland landscapes and the habitat quality of rare and endangered waterbirds. Therefore, clarifying the spatiotemporal dynamics of vegetation cover serves as the foundation for scientific conservation and refined management of this coastal wetland. Numerous studies have employed the Normalized Difference Vegetation Index (NDVI) to investigate vegetation changes in this region. Nevertheless, most studies have only extended to 2020 and rarely adopted annual maximum NDVI data. This metric can effectively eliminate cloud contamination and phenological interference, thereby reflecting actual vegetation growth conditions. Since 2020, water and sediment regulation has intensified, and large-scale Spartina alterniflora control efforts have been carried out. There is an urgent need to update vegetation monitoring data through 2025 to reveal recent wetland succession characteristics against the backdrop of ecological and environmental changes. This study collected annual maximum NDVI datasets from 2016 to 2025 at a spatial resolution of 250 m. Following preprocessing procedures including atmospheric correction, quality masking, projection transformation, and boundary clipping, standardized annual NDVI raster data were generated. The Mann-Kendall non-parametric test was employed to identify pixel-scale vegetation change trends. NDVI values were classified into five grades: no vegetation, low cover, medium cover, high cover, and extremely high cover. Transition probability matrices, change frequency, and stability indices were further calculated to characterize vegetation cover type conversion features and their spatial stability patterns. The results were as follows. Over the decade, the overall vegetation pattern of YRDNNR remained relatively stable. Water bodies and bare land constituted the dominant landscape (approximately 40.00%), showing a slight upward trend. Areas with extremely high vegetation cover accounted for approximately 30.00% of the total area, with significant interannual fluctuations. Vegetation cover type conversions exhibited pronounced asymmetric characteristics: low cover and high cover vegetation demonstrated weak stability, with retention rates of only 44.95% and 42.53%, respectively, frequently transitioning to medium cover vegetation or no vegetation areas. In 61.54% of the reserve area, vegetation cover types remained unchanged, indicating relatively high overall ecosystem stability. Areas with active vegetation changes were primarily distributed in the water-land ecotone, driven jointly by natural and anthropogenic factors including soil salinization, Spartina alterniflora invasion and control, ecological water supplementation, and wetland restoration projects. In conclusion, the YRDNNR maintained stable vegetation patterns from 2016 to 2025. The structural changes involving the expansion of water bodies, bare land, and medium cover vegetation are conducive to waterbird habitat conservation. This study suggests that future long-term ecological monitoring and targeted wetland restoration decisions should prioritize the water-land ecotone.