Abstract: The Golmud river basin is a typical arid inland river basin in the northwest of China. Groundwater serves as an important water source for both dominant vegetation ecosystems and urban water supply. Balancing the groundwater exploitation and vegetation ecological water demand holds significant theoretical and practical importance for protecting the fragile ecological environment during groundwater exploitation. To evaluate the potential ecological risk of the ecosystem in the Golmud river basin under different hydrological scenarios, a groundwater flow numerical model was developed. The ecological risks under current and planned groundwater abstraction scenarios were evaluated using a dual-indicator framework incorporating river ecological water demand and suitable groundwater table depth thresholds for dominant vegetation species. The suitable groundwater depth ranges for Phragmites australis, Tamarix chinensis, Apocynum venetum, and Nitraria tangutorum are 0.2–3.5 m, 1.0–5.0 m, 1.0–4.0 m, and 1.0–3.3 m, respectively, with optimal groundwater depths of approximately 1.2, 2.0, 2.6, and 1.8 m. The maximum groundwater depth threshold required for sustainable vegetation growth was determined to be 5.0 m, while the ecological water demand of the Golmud River was estimated to be 3.53×10⁸ m³/a. Under the current groundwater abstraction scenario (1.43×10⁸ m³/a), the remaining river water volume was 4.80×10⁸ m³/a, indicating a near balance between groundwater withdrawal and recharge and sufficient water availability to meet ecological demands. Under the planned abstraction scenario (2.55×10⁸ m³/a), the remaining river water volume in different hydrological years could still satisfy the ecological water demand. The ecological impacts under different hydrological conditions were mainly concentrated in the areas dominated by Phragmites australis, whereas vegetation distributed in the northern part of the basin was minimally affected. This study determines the scope and extent of potential ecological risks under different scenarios, providing support for the delineation of risk management zones and the formulation of policies for rational groundwater exploitation and ecological protection in the catchment. It also offers insights for research on ecological risks in areas of northwestern China where vegetation relies on groundwater.