The typical working conditions are selected to calculate and analyze the various characteristics of water level，discharge，flow velocity，specific drop，etc. in the beach section through the unsteady mathematical model，and the influence of daily regulation on the flow conditions of Shaoqibei reach is obtained. The results show that under two kinds of daily regulation conditions，the unsteady flow from unsteady flow to Shaoqibei River has a certain influence on the flow conditions of the downstream channel and the control reach and maintenance facilities of the channel under the condition of unsteady flow from 1.01 m to 1.37 m. The influence on the channel’s flow condition under 4.5 m daily variation is greater than 3.0 m. The analysis result provides support for further optimizing the hub shipping scheduling scheme and waterway maintenance measures.