Abstract: Revealing the transverse distribution characteristics of sediment-laden flow and sediment factors can provide a theoretical basis for utilization of lower Yellow River beach area and river management. By means of experimental simulation and theoretical research, the generalized model test of floodplain flood evolution is carried out, and the transverse distribution characteristics of sediment factors of sedimentladen flow in curved compound channel under the condition of beach vegetation are analyzed. Meanwhile, the theoretical model of transverse distribution of velocity and sediment concentration based on the momentum equation considering the inertial force of the lateral secondary flow and river curvature is verified. The results show that:（1）The slowing effect of beach vegetation on the flow velocity is significant；（2） The arrangement of full vegetation on the beach has a uniform effect on the velocity distribution of the beach, which can reduce the phenomenon of excessive velocity at the foot of the beach and increase the velocity effect in the main channel；（3） Through five numerical examples, the lateral velocity distribution model of a curved compound channel with beach vegetation is tested and, in general, the analysis model is consistent with the experimental results.