[Objective] This study aimed to quantitatively assess the spatial distribution of geologic hazards in the Three-River-Source National Park, explore their impact on the ecological security pattern, and provide countermeasures for regional disaster mitigation and prevention and land-use planning adjustment. [Methods] Based on GIS and the information value model, 12 assessment factors were selected from the perspective of disaster preparation and induction of geological disasters to assess the geological disaster risk of the Three-River-Source National Park, and analyze it in combination with the construction of ecological corridors and optimization of ecological security pattern. [Results] 1) The area of high-risk and extremely high-risk geological hazards of the Three-River-Source National Park is 25 614.32 km², accounting for 20.81% of the total area. 2) The main controlling disaster-forming and disaster-inducing factors of geological disasters of the Three-River-Source National Park are slope（information value=6.238 52） and distance from rural residential areas（information value=13.270 66）. There is a high correlation between geological disaster sensitivity and human activities. 3) The identified area of ecological sources is 26 833 km², with 55 ecological corridors extracted（6 080.15 km²）. Functional zones include core protected areas（39 613.58 km²）, ecological conservation areas（67 261.84 km²）, recreation and display areas（10 143.44 km²）, and traditional utilization areas（6 081.34 km²）, etc. 4) The ecological security pattern of the Three-River-Source National Park is greatly affected by geological disasters. The main affected areas are the core protected areas of the Yangtze River Source Park（65.30%）, the Lancang River Source Park（77.90%）, and the traditional utilization area of the Yellow River Source Park（88.97%）. The Yellow River Source Park is the park with the highest risk in the corridor. [Conclusion] There are obvious spatial differences in the impact of geological hazards on the ecological security pattern in the Three-RiverSource National Park, and corresponding preventive and control measures should be taken in a zoned and categorized manner.