There are various distribution patterns of vegetation in natural rivers. In order to investigate the influence of rigid submerged vegetation on the flow characteristics under different layout patterns, the experiment was carried out using the glass sink in the laboratory to simulate the open channel with rigid submerged vegetation. The results show that the arrangement of rigid submerged vegetation has a significant effect on the flow characteristics of open channels. The water depth, vegetation resistance coefficient and vegetation roughness coefficient under vegetation layout all increase, and the spicific staggered arrangement>patch type arrangement > long strip arrangement. Both the flow velocity and the Reynolds number decrease, showing a long strip arrangement>a patch type arrangement>a staggered arrangement. The roughness n decreases as the average flow velocity and the hydraulic radius VR increases.