The Ouchi（guan）station is located at the Ouchi reach of the fourth channels of the Yangtze River,which is the control station of the Ouchi river branch of the fourth channels diversion of the Jingjiang River.The relationship between water level and discharge is mainly affected by flood fluctuation,cross-section scouring and silting,backwater jacking of Dongting Lake,etc.the legal line of connecting time series rope sleeve is relatively complex,and there are many flow measurements.Through the single value analysis of hydrological data of Ouchi（guan）station from 2016 to 2020,Xinchang station is selected as the drop auxiliary station,and the trial and error method is used to determine the optimal single value scheme.The results show that the single value analysis result of water level discharge relationship is good,which meets the requirements of the current hydrological integration specification,optimizes and reduces the number of discharge tests,and improves the work efficiency.