Water Users Association (WUA) is a nonprofit organization with legal person status. Its function mainly focuses on participating in Water Right Exchange, distributing water right, promoting the transfer of water rights, and so on. The transfer of land management right and the intensive and scale management of land brought about by the reform of “Separating Rural Land Ownership Rights, Contract Rights, and Management Rights” have brought challenges to the operation of WUA, and their foundation, function orientation and specialization level are all facing new challenges. From the advanced experience of other countries, under the background of the “Separating Rural Land Ownership Rights, Contract Rights, and Management Rights”, WUA needs to be optimized from the aspects of service object, functional transformation, ability enhancement, and so on. The nonfarmer water users should be brought into the service object, the functional orientation based on water right exchange and supplemented by distribution needs to be clarified, and the comprehensive ability should be improved with the help of systematic training and professionals, so as to meet the new demands of agricultural development.