Abstract: The equitable allocation of water resources is of great significance for promoting the balanced development of regional water resources and economic and social space.The Theil Index is selected to characterize the equity of water distribution at different levels between regions and among water users within a region.An optimal allocation model of water resources is constructed with the minimum water shortage rate, the maximum economic benefit and the highest fairness as the objective function.The application research is carried out aiming at the Henan section of Changjiang River to Huaihe River Water Diversion Project, which supports the rise of the central China.The results show that after the water transfer project, the water shortage rate of the water receiving area in Henan section will be reduced to 10.42 % and 5.48 % in 2030 and 2040,which effectively adjusts the water supply structure of the water source, and can alleviate the problems of groundwater overexploitation and ecological water use.The Theil Index of water receiving area in Henan section is 0.479 and 0.420 in 2030 and 2040,respectively.The equity of water resource allocation would be significantly improved.It demonstrates that the differences among different water users in the region play a leading role in the equity of water resource allocation in the water receiving areas of Henan section.