Based on the InVEST model, Hierarchy of Needs Theory, and ecosystem service supply-demand analysis, we utilized Linkage Mapper and other tools to extract ecological sources, corridors, and pinch points in the Sichuan Basin from 2005 to 2020, following the least-cost path theory. The ecosystem service supply-demand relationship was analyzed to construct the ecological security pattern of the basin. Spatially, ecosystem service supply and demand in the Sichuan Basin exhibited a negative correlation. Despite an overall ecological surplus (supply exceeding demand), spatial mismatches between supply and demand intensified regional contradictions. From 2005 to 2020, the area of ecological sources in the basin was 68700km², 63900km², 63100km², and 64800km², respectively, presenting a “dense periphery-sparse center” ring-shaped distribution. The total length of ecological corridors across four periods increased continuously (6693.38km, 8342.29km, 8594.62km, and 14130.94km), forming a “periphery-connected, sparse-center, dense-east” network structure. Ecological pinch points were clustered at source junctions, while obstacle points were concentrated near fragmented source patches, particularly in the eastern parallel ridge-valley region. Integrating ecosystem service supply-demand dynamics and existing ecological security patterns, we proposed an optimized protection framework termed “Three Belts, Four Zones, and Five Cores”. Three Belts: East-west axial belts in the basin’s southern and northern regions, and a north-south axial belt in the eastern basin. Four Zones: Ecological security protection zone (eastern Sichuan), ecological restoration zones (western and northern Sichuan), and an ecological fragility recovery zone (central Sichuan). Five Cores: Key connectivity nodes in the southern basin and the eastern parallel ridge-valley area.