When multiple industries share a river, they compete for available water resources. In order to settle conflicts and ensure industrial stability, it is important for river basin managers to develop a water allocation plan. In addition, there is a correlation between water demand and output in different industries, which affects water allocation plans. From the perspective of the river basin government, this paper constructs a flow distribution model among the three major industries of industry, agriculture, and service. The river basin government allocates water resources to the stability of the three major industries. The water consumption of various industrial sectors is centered on their own vital interests. Different industries have different characteristics and restrictions on water consumption. The study also considered transactions in different industries on the water market, using dynamic programming methods to simulate this water allocation. This allocation model is different from the traditional industrial water allocation model, and considers the correlation between the water demand and output value of different industries. The results show that a reasonable understanding of the interrelationships between industries will be more helpful to decision makers and a fundamental guarantee for sustainable use of water resources.