The bed under the erosion of the current is the place where the moving mass moves. Studying the influence of the micro-bed surface shape on the moving mass is helpful for exploring the law of the moving mass on the bed,and it has a good promotion effect on river management. After a series of tank experiments,a representative video was selected,and image recognition technology was used to mark moving objects in the video,analyze the movement law of the moving mass on the bed surface,and explore the effect of water scour on the shape of the moving mass.The results show that the direction of motion of the large particles on the bed and the direction of the water flow form an angle of less than 30° with a straight path;the movement of small particles on the bed surface is affected by the near-bottom velocity,and the aggregates will branch off the flow on the surface of the riverbed,causing the direction of small particles to change at all times.The angle with the direction of water flow is in the range of 0°~90°,and the acceleration between the two aggregates is more obvious;aggregates of different morphologies have different stability,and the aggregates can be transformed into each other.