Abstract: The Qinling-Daba Mountains play a critical strategic role in China's ecological civilization construction and serve as a key ecological barrier in the national ecological security framework. However, the Shaanxi section of the Qinling-Daba Mountains faces significant challenges, including incomplete ecological background data and the inadequate delineation of key areas requiring ecological protection, which hinder regional ecological protection and sustainable development. This study used high-resolution remote sensing imagery to systematically examine the evolution of the ecological patterns prevailing in the region from three perspectives: ecosystem structure, ecological quality, and ecosystem function. The study also identified key areas providing functional ecological services. The findings were: (1) From 2000 to 2023, the areas of forest, residential and industrial-mining land, and wetlands in the region exhibited a consistent growth trend, increasing by 1 122.10, 542.75, and 69.78 km², respectively, with an evolving landscape pattern characterized by stable, dominant forests, the progressive fragmentation of farmland areas, and the rapid spatial agglomeration of urban areas. (2) There was overall improvement in the ecological quality of the region, with approximately 60.90% of the area experiencing an increase in ecological quality, while only about 4.74% showed a decline in quality, primarily in parts of the Hanzhong and Guanzhong plains. The areas critical for water and soil conservation represented 22.89% and 12.43%, respectively, mostly concentrated in the Qinling-Daba Mountains. (3) Based on the changes in ecosystem characteristics and service functions, the Shaanxi section of the Qinling-Daba Mountains was classified into three functional areas: ecological improvement areas, ecologically stable areas, and ecologically degraded areas. This zoning provides a scientific basis for implementing region-specific measures, facilitates the formulation of targeted ecological protection and restoration policies, and is of significant importance for promoting regional ecologically sound communities and high-quality development.