Construction of ecological security pattern is of great significance for ensuring ecological security at regional scale. It takes an important role on optimizing ecological national land space. Taking Lhasa River Basin as the research area, the ecological security pattern paradigm was constructed based on the ecological source-resistance surface-ecological corridor at the region scale. Soil conservation, water conservation, carbon sequestration, and habitat quality were evaluated as key ecosystem services of the Lhasa River Basin. Ecological sources were identified by the importance grades of ecosystem services. Land cover types, normalized difference vegetation index, relief, slope, distance to roads, distance to water were selected as the main resistance factors. The comprehensive resistance surface was generated by calculating the weight of resistance factors using the entropy weight method. Ecological corridors were identified by using Linkage Mapper tool based on the least cost path theory. Ecological nodes were extracted on the basis of ecological corridors. The ecological security pattern of the Lhasa River Basin was constructed at the watershed scale. The results showed that 20 ecological sources were extracted, with a total area of 2531.42 km². Ecological sources accounted for 7.77% of the total area of the study area. 36 ecological corridors were extracted, with a total length of 916.87 km. The distribution pattern of ecological corridors was parallel to the main stream of the Lhasa River in shape of "two" in Chinese. 13 ecological nodes were extracted, concentrated in bare land, bare rock and low coverage grassland in the Lhasa River Basin. Finally, a plane-line-point structure ecological network was formed, which composed of ecological sources, ecological corridors, and ecological nodes. The results provide data support for the coordination of ecological security and ecological economy in the Lhasa River Basin, and provide scientific reference for regionally ecological protection and sustainable development.