The data set includes the observation data of river water level and velocity at No.7 point in the dense observation of runoff in the middle reaches of Heihe River from January 1, 2014 to December 28, 2014. The observation point is located in Heihe bridge, Pingchuan Township, Linze County, Zhangye City, Gansu Province. The riverbed is sandy gravel with unstable section. The longitude and latitude of the observation point are n39 ° 20'2.03 ", E100 ° 5'49.63", with an altitude of 1375m and a channel width of 130m. In 2014, sr50 ultrasonic distance meter was used for water level observation, with acquisition frequency of 30 minutes. Data description includes the following two parts: Water level observation, observation frequency 30 minutes, unit (cm); The data covers the period from January 1, 2014 to December 28, 2014. Flow observation, unit (m3); According to the monitoring flow of different water levels, the flow curve of water levels was obtained, and the change process of runoff was obtained by observing the process of water levels.The missing data are uniformly represented by the string -6999. For information of hydrometeorological network or station, please refer to Li et al.(2013), and for observation data processing, please refer to He et al.(2016).