Abstract:The digital transformation of water conservancy is an important starting point of smart water conservancy construction. According to the architecture of “one cloud, one warehouse, one platform”, a “four horizontal and three vertical” basic architecture for digital water conservancy is established. Two development models for data sharing and business collaboration are built, and the data middle platform and business middle platform are studied. Water conservancy applications for Provincial, municipal and county are developed based on the “five unified technologies”, such as a unified user system, a unified work portal, a unified data warehouse, a unified water conservancy map, and a unified security defense. The theories and methods are carried out on Zhejiang digital water conservancy. The results show that the research are helpful to solve the problems of “information islands” of water conservancy data resources and “respective management” of water conservancy applications.