Based on the prototype data of water and sediment from 1972 to 2016 at Fuyang sluice station of Shaying River，using tools such as SPSS，MATLAB，etc.，and adopting R/S analysis and wavelet analysis methods，we study the characteristics and change trend of water and sediment from Sanbacun reach. Based on the measured topographic data of the project reach in 2017 and 2019，we analyze the recent changes of river regime and characteristics of riverbed erosion and deposition to reveal the main characteristics and laws of riverbed evolution in this reach. The results show that under the premise of no systematic increase or decrease of runoff，the sediment discharge and sediment concentration in the river course are obviously decreased；The sediment discharge and sediment concentration in the river reach of the project are predicted to be decreased in the future；Under the natural evolution condition，the floodplain of the river course of the project section is basically stable，the main channel is slightly scoured，the scour range is small，and the river course is relatively stable；The project will not fundamentally change the scouring and silting characteristics of the reach. In the long run，the main stream of the bend after the project tends to open a new channel，and the riverbed will still maintain the trend of scouring and cutting down.