Abstract: As critical ecological transition zones, salt marshes play significant roles in the global carbon cycle and coastal protection. The total area of saltmarshes in Hebei Province is 290.96 hm², with the main vegetation types being Phragmites australis, Suaeda salsa, and Spartina alterniflora. However, due to insufficient freshwater supply, expansion of mariculture, coastal erosion, and alien species invasion, the saltmarsh ecosystems in Hebei Province are facing issues like vegetation degradation and habitat fragmentation. Existing studies still lack systematic diagnosis of their long-term dynamic changes and stress factors. This study employs a multi-scale ‘satellite-UAV’ monitoring system, integrating satellite data (e.g., GF-2, Landsat) with UAV aerial surveys, and combines the pixel dichotomy model with field plot investigations to systematically characterize the spatiotemporal evolution characteristics of saltmarsh vegetation. The results show that: ①From 2000 to 2023, the typical saltmarsh ecosystems in Hebei Province were in a slow degradation stage due to the influence of ecological factors such as climate, hydrology, salinity, and soil conditions. Among them, the saltmarsh area at Yanghe Estuary decreased by as much as 65.5%, showing the most significant degradation trend; the saltmarsh area at Luanhe Estuary decreased by 36.7%; the saltmarsh area at Yuedao Island showed a trend of first decreasing and then increasing with a reduction of 35.9% from 2005 to 2015 and a slight recovery from 2015 to 2023; at Nanpaihe Estuary, due to the invasion and subsequent control of Spartina alterniflora, the saltmarsh area increased from 4.20 hm² in 2005 to 66.38 hm² in 2015, and then decreased to 3.98 hm² by 2023. ② In terms of vegetation community characteristics, a total of 36 plant species were recorded in the Yanghe Estuary saltmarsh, with an average quadrat coverage of 83.75%; Shannon-Wiener diversity indices ranged from 0.252 to 1.622, and Simpson’s diversity indices ranged from 0.052 to 0.779, all of which were superior to those of other regions. In contrast, only 16 plant species were found in the Nanpaihe Estuary saltmarsh, predominantly Suaeda salsa and Phragmites australis. However, its average quadrat coverage reached 72.06%, and the average biomass was 0.89 kg/m², the highest among the four study regions; ③Vegetation status assessment reveals that the saltmarsh vegetation in Yuedao Island was classified as Grade Ⅰ (stable), while those in Luanhe Estuary, Yanghe Estuary, and Nanpaihe Estuary were classified as Grade Ⅱ (damaged). This study plays an important role in enhancing the stress resistance and stability of saltmarsh ecosystems, provides reliable data support for saltmarsh ecological restoration, and offers a scientific basis for the restoration of ecological functions of coastal wetlands.