Based on analyzing the present situation of water supply system in Xi'an,the paper established a joint operation model multiple water sources under the control of scheduling rule. On the basis of analyzing the relevant elements in the process of water user and water supplier as well as the relationships among them, it summarized the main objectives in the system and set up the sketch of joint operation system network of multiple water sources for meeting the objective and requirement of joint water transfer. According to the historical hydrological data from 1956 to 2010 and the predicted water demand for city development planning, the paper analyzed the balance of supply and demand and got the results of joint water transfer under different schemes.Aiming at the contradiction of water resources supply and demand, it put forward some concrete response measures.