Abstract: The gravelly soil widespread in norther area of Xinjiang is chosen to reconstruct bank slope. Large scale model tests on hydraulic scour of gravelly soil bank slope are carried out. A new observation method, three-dimensional laser scanning technique, is introduced to observe erosion damage of the bank slope. Based on the results of 3D laser scanning and traditional measurement methods, according to the failure characteristics at different stages, the failure of the bank slope is divided into three stages, namely scour damage stage, local instability stage and overall instability stage. The instability process of deformation and the failure mode of the gravelly soil bank slope are determined. Based on the test results, the formulae for calculating the stability and predicting the local buckling failure height are derived. Through this study, the relation between the scour damage phase and the local buckling stage is established, and the failure mechanism of typical gravelly soil bank slope is deeply revealed.