With the rapid development of economic and social Nanchuan River basin in Qinghai Province, the rapid increase in the level of industrialization and urbanization, water supply and demand have become increasingly prominent. Based on estuary hydrological station data of Nanchuan River downstream, the paper used a variety of methods to Nanchuan River 750substations at the design section of the hydrologic calculation obtained hydrological data witch can provide a scientific basis for reasonable development and utilization of water resources of the territory and the development of flood control planning and urban development layout.