[Objective] The key influencing factors of urban ecological water security in Gansu Province were comprehensively evaluated in order to provide a reference for coordinating the relationship between regional ecology, production and life. [Methods] Based on social, economic, ecological, and water resource and development factors, an ecological water use evaluation system was constructed. The weights for each factor were obtained by a combination of analytic hierarchy process (AHP) and the entropy method. The level of ecological water security was categorized, and the main influencing factors of ecological water security were determined. [Results] ① In 2020, the overall ecological water security index values for Jiayuguan, Lanzhou, and Gansu Province were more than 0.5 (the basic safety level), while the values for 12 of the cities were at relatively unsafe levels. ② The level of ecological water security in the core area from 2011 to 2020 was low, mainly affected by the ecological benefits subsystem. ③ The coverage area of green space, proportion of ecological environment water, per capita green space area of parks, and urbanization level were the main obstacles affecting the level of ecological water security, contributing more than 45%. [Conclusion] The ecological water security of each urban area in Gansu Province does not appear to be optimistic, and it will be necessary to improve ecological benefits in order to improve the ecological water security of each urban area in Gansu Province.