Agriculture especially plantindustry of Zhangye City in Gansu Province of China consumes directly and indirectly a big amount of water, and the export and import of regional agricultural products have also significant effect on the export and import of water in Zhangye. The excessive dependence on plantindustry of economy leads to excessive dependence on water resources in Zhangye, and it causes a great pressure on water supply. Based on the input-output model, a multiplier analysis of water resource benefit at regional level is conducted in this paper. The results show that it is important for the solving of water crisis in inland arid area to adjust industrial structure, upgrade the industries, develop a high efficiency water-saving agriculture, reduce proportion of agriculture, especially planting at the level of regional economy.