Abstract: Analyzing the impacts of vegetation distribution on the water transport capacity of rivers and the transport capacity of solutes such as pollutants is of great significance for reducing pollutants in downstream rivers and protecting the ecological environment of rivers. Based on the lattice Boltzmann numerical simulation method, the obstruction effect of vegetation is generalized as vegetation roughness, and the D2Q16 multi-velocity shallow water model is used to simulate and calculate the flow field in the river channel with spaced vegetation zones. The calculated flow field information is then combined with the D2Q5 convection-diffusion The pollutant concentration field obtained by the model is coupled to study the influence of vegetation on the flow field and pollutant transport. The results are as follows. The flow velocity decrease in the vegetation area of the river longitudinal section and the flow velocity increase in the transition area and central area are linearly positively correlated with the vegetation density. The flow velocity in the central area of the cross section is much greater than the transition area and vegetation area. The flow velocity in the vegetation area and the central area are linearly distributed. Moreover, the flow velocity in the transition zone has a quadratic power correlation with the vegetation density, and the attenuation amplitude of the pollutant concentration has a positive correlation with the distance between vegetation zones. Vegetation can change the trajectory of pollutant transport and can effectively reduce the concentration of pollutants downstream of the river. This study can provide a reference for the appropriate density and spacing of artificially arranged vegetation in river channels in the construction of urban artificial ecological landscapes.