Abstract: The studies of sustainable utilization of water resources help to promote scientific water usage in the middle reaches and protect downstream ecology in the Heihe River Basin. The exploitation in the middle reaches of the Heihe River resulted in the deviation of the discharge of Zhengyixia Gorge from the targets of the '97 national water diversion scheme. In this article, taking the water usage of the Zhangye, Linze and Gaotai irrigation areas as the primary research targets, an optimization programming model for sustainable utilization of water resources is established based on multi-objective and multi-constraint equations. The studies demonstrate that the discharge of Zhengyixia Gorge is mostly affected and controlled by the runoff of Yingluoxia Gorge, the irrigation water volume and the discharge of groundwater from the Bridge to Zhengyixia Gorge. The results show that water resources in the middle reaches of the Heihe River can ensure water consumption for the current irrigation area and simultaneously meet the targets of the '97 national water diversion scheme by decreasing the irrigation quotas through water saving measures, which are the effective measures to solve the water consumption conflicts between the middle reaches and the lower reaches, and are crucial to the protection of artificial oases in the middle reaches and downstream ecology.