The Three-river Source Region is an essential component of the ecological barrier on the Qinghai-Tibet Plateau. Scientifically establishing an ecological security pattern holds significant importance in fortifying the ecological security barrier of the Three-river Source Region and maintaining sustainable development. This paper couples the Analytic Hierarchy Process (AHP) with the Entropy Weight Method, utilizing methods such as ecosystem services, Morphological Spatial Pattern Analysis (MSPA), and landscape connectivity to identify ecological sources of different levels. An ecological resistance surface is constructed by integrating land-use types and synthesizing ecological sensitivity with terrain niche index. Additionally, the Linkage Mapper tool is employed to identify ecological corridors of different categories, thus establishing the ecological security pattern in the Three-river Source Region. The findings indicate: (1) The ecological sources in the Three-River Source Region cover an approximate area of 52371.30km², constituting 13.70% of the total study area. These areas are predominantly characterized by large-scale irregular patches, displaying a spatial distribution pattern with a higher concentration in the eastern part and a lower concentration in the western part. Specifically, the first-level ecological sources cover an area of approximately 48290.06km², representing 92.21% of the total ecological sources. These primary ecological sources are predominantly concentrated in the central and southeastern regions, characterized by higher significance in terms of ecosystem services. (2) A total of 328 ecological corridors are identified, demonstrating a spatial pattern characterized by dense concentration in the central and eastern regions and sparse distribution in the western region, resembling a spiderweb. Overall, there is an east-west-oriented undulating extension trend. (3) This paper identifies the ecological pinch points covering 1796km², ecological obstacle points covering 2490km², primarily located in the southern part of the research area in Zaduo County. This paper identifies 61 ecological breakpoints, predominantly concentrated in the southeastern region of Zhiduo County. (4) We construct the "Three Zones, Three Belts, and Multiple Points" ecological security pattern, designating the "Three Zones" as the Ecological Nurture Development Zone, the Central Restoration Key Zone, and the Western Ecological Protection Zone. The "Three Belts" encompass the Maintenance Belt of Green Water and Lush Mountains, the Key Belt for Biological Protection, and the River Source Security Construction Belt. Furthermore, we identify the core restoration points as part of the "Multiple Points" strategy. The paper considers the ecological conditions within different small regions, enabling tailored ecological development. The research outcomes can offer scientific recommendations for optimizing ecological conservation in the Three-river Source Region.