In order to understand the mechanism of bubble curtains in shallow water, clarify their hydrodynamic characteristic parameters, and investigate the influence of water depth and air supply rate per unit width on these parameters, a numerical simulation study on the hydrodynamic characteristics of bubble curtains was conducted using OpenFOAM based on the two-fluid model. Methods were proposed for the estimation of vertical velocity, horizontal flow velocity, and maximum efficiency of bubble curtains in shallow water. The results show that in the range from a water depth of 0.5 m to 0.2 times the water depth, the central velocity of the bubble plume remains constant along its path, and the horizontal width of the bubble plume increases linearly. At a distance of 0.25 times the water depth from the bubble curtain, the surface flow velocity reaches its maximum, and the thickness of the horizontal flow is the minimum. Then, the surface flow velocity decreases linearly along the flow path. The horizontal thickness ranges from 0.15 to 0.4 times the water depth.