Abstract: As critical ecological transition zones, saltmarshes 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, affected by factors such as insufficient freshwater supply, expansion of mariculture, coastal erosion, and alien species invasion, saltmarsh ecosystems 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 ‘satellite-UAV’ multi-scale 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, 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 area of the Yanghe Estuary saltmarsh decreased by as much as 65.5%, indicating the most significant degradation; The area of the Luanhe Estuary saltmarsh decreased by 36.7%; The area of the Yuedao Island saltmarsh first declined and then rebounded, experiencing a reduction of 35.9% from 2005 to 2015 and a slight recovery from 2015 to 2023; Affected by the invasion and subsequent control of Spartina alterniflora, the area of the Nanpaihe Estuary saltmarsh increased from 4.20 hm² in 2005 to 66.38 hm² in 2015 and then decreased to 3.98 hm² in 2023. ② In terms of vegetation community characteristics, a total of 36 plant species were documented in the Yanghe Estuary saltmarsh, with an average plot coverage of 83.75%; The Shannon-Wiener diversity index of this area ranged from 0.252 to 1.622, and Simpson’s diversity index ranged from 0.052 to 0.779; All these indicators 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 plot coverage reached 72.06%, and the average biomass was 0.89 kg/m², which was the highest among the four study areas; ③Vegetation status assessment reveals that the saltmarsh vegetation in Yuedao Island is classified as Grade Ⅰ (stable), while those in Luanhe Estuary, Yanghe Estuary, and Nanpai Estuary are classified as Grade Ⅱ (damaged). This study not only provides reliable data support for saltmarsh ecological restoration but also plays an important role in enhancing the stress resistance and stability of saltmarsh ecosystems, and offers a scientific basis for the restoration of ecological functions of coastal wetlands.