The ecological protection and high-quality development of the Yellow River Basin has been determined as a major national strategy. Ecological security pattern is considered as one of the three strategic patterns of land and space development and protection, which refers to the overall health, sustainability and perfect ecological functions of the ecosystem. Scientific understanding and evaluation of regional ecological risks and construction of ecological security pattern are conducive to comprehensively improving the level of regional ecological security. At present, for the construction of ecosystem security pattern at home and abroad, a relatively perfect pattern construction model with "source identification, resistance surface construction, corridor extraction and determination of security pattern" as the basic framework has been formed for research. In this paper, InVEST (Integrate Valuation of Ecosystem Service and Tradeoffs Tool), ArcGIS and other software are used to select four indicators that can represent the main ecological contradictions in Gansu section of the Yellow River Basin, including water conservation volume, carbon fixation and oxygen release volume, soil conservation volume and ecological and environmental quality. The index importance method is used to extract the ecological source, as well as the land use degree, population density and land average GDP to identify the spatial pattern of ecosystem service demand. Finally, the MCR (Minimum Cumulative Resistance) model is used to extract the ecological corridors between the source areas and between the source areas and the high-demand areas, thereby identifying and constructing the regionally ecological security pattern. The results show that:(1) the total area of ecological source in Gansu section of the Yellow River Basin is 4.59×10⁴ km², accounting for 32.1% of the total area of the research area, mainly distributed in the central, southern and western Gansu Province. (2) The total area of high demand area for ecosystem services is 2.18×10⁴ km², accounting for 15.2% of the total area of the research area, mainly distributed in the urban built-up areas of the central and eastern Gansu Province, with poor spatial matching between ecosystem service supply and demand. (3) The total length of the ecological corridor is 2908.3 km. From the overall pattern, it forms two main corridor axes in east-west and north-south directions. In this research, the ecological demand space is taken into account in the identification of ecological corridors, and more attention is paid to the areas with high demand and low service, and then the optimization suggestions of watershed ecological security pattern based on "two belts-three areas" are put forward, hoping to provide scientific reference for establishing watershed ecological comprehensive management mechanism and promoting watershed protection, governance and high-quality development.