Abstract: The detection of riverbed structure is the key to study river-groundwater transformation. Single physical exploration method is usually of low accuracy in the detection of complex riverbed structure. This study jointly adopt Doppler acoustic velocity meter, geological radar and high-density resistivity method to investigate riverbed morphology and detect sediments distribution characteristics in the typical working area of Huaibei Plain. A complete technical system of joint inversion of riverbed lithological structure characteristics is accordingly constructed, achieving a good identification effect. The results show that: the upstream of the Xinbianhe River control gate is "butterfly-shaped" with uniform riverbed structure and small variation of sediment thickness. The shape of downstream riverbed fluctuated greatly under the influence of the sub-dam, with the sediment thickness of 0.8~1 m. The channel of Guohe River is semi-oval in shape, and the bottom mud is thin on both sides but thick in the middle. Seriously disturbed by sand pumping, the riverbed in Hancun section is high in the middle and low on both sides, resulting in uneven distribution of sediment. There is a weak permeable layer (silty clay) between Lianghekou section and a confined aquifer, and the local phreatic aquifer distributes unevenly. The practice has proved that the joint inversion of various techniques can corroborate mutually in riverbed morphology detection and improve the reliability and accuracy of results interpretation, providing support for the study of river-groundwater transformation.