Abstract: This study developed a joint water supply system to improve the joint scheduling compensation of water transfer and water supply from local water resources for the Shaanxi Han river-to-Wei river water transfer (HWWT) project and the Shaanxi Heihe river diversion (HRWT) project. This system includes a structure diagram of the water resources system and a water dispatch simulation model. It simulates and calculates various supply schemes that were designed for two types of HWWT water allocation and a variety of HRWT water supply orders. Using this system, we optimized the supply schemes for 2020 and 2030, defining a monthly water supply reliability to verify the simulations. The results show that a better scheme is to allocate HWWT water in demand assignment by the order of water supply to city users. And in 2020 the water supply guarantee rate would reach 95% for comprehensive city life use while over 90% for industrial enterprises and ecological environment. In 2030, all the guarantee rates would exceed 90%. At the operation stage of HWWT project, the HRWT project will supply to the city with its surplus water after meeting the demands by river base flow and reservoir irrigation. This significantly improves the reservoir irrigation guarantee rates up to a level of higher than 75% in 2020 and 2030.