Abstract:The compilation of hydrological data is an important part of the hydrological work. The compilation of traditional hydrological data has the problems of complex data reorganization, time-consuming work, poor timeliness of data, and low applicability of data results. Taking the case of the design and application of on-line hydrological data compilation system in Yunnan Province as an example, the key points, characteristics and application effects of the online reorganization system for hydrological data are introduced. Through the construction of on-line hydrological data compilation system , the efficiency of hydrological data reorganization can be improved, the timeliness of hydrological data services can be enhanced, and the utilization rate of hydrological data can be improved, providing new ideas for the compilation of hydrological data in other regions.