In plain rivers,sediment transport is dominated by suspended load.When vegetation is present in the flow,significant changes occur in the flow field,which in turn affect the settling velocity and spatial distribution of suspended particles.In this study,a three-dimensional hydro-sediment numerical model incorporating the effects of rigid vegetation is developed based on the OpenFOAM solver driftFluxFoam.The model is validated through flume experiments involving flow around cylinders and partition plates.Four vegetation submergence ratios （h/H=0.4,0.6,0.8,1.0） are considered to simulate flow structures and suspended sediment distribution around vegetation under different submergence conditions.The results show that as vegetation submergence increases,the influence of submerged vegetation on flow velocity is confined to the vegetation layer.The vertical velocity decays significantly at 5D downstream of the vegetation,with a maximum increase in instantaneous velocity of approximately 55%.Bed shear stress increases within 5D upstream of the vegetation,the critical emergent vegetation shear stress is about 70% higher than that of submerged vegetation.A peak in shear stress forms along the centerline at 5D downstream,with low-stress zones appearing at 2D on either side of the centerline,and the wake region shows limited influence.The variation range of suspended sediment concentration gradually narrows,and the annular low-concentration zone at the vegetation base decreases.Submerged vegetation has a limited impact on near-bed longitudinal suspended sediment concentration differences,while critical emergent vegetation shows the opposite trend.The normalized time-averaged suspended sediment concentration at 50D downstream (CE/CA) is approximately 1.46.