According to the design conditions of a siltation promotion project located in the Yangtze River estuary,the near-bottom hydrodynamic characteristics of a new hollow tetrahedron siltation promotion embankment is studied by model-test method.Test results show that:1)The maximum value of the near-bottom turbulence intensity,the minimum value of the near-bottom average horizontal velocity,and the direction changing of the near-bottom average horizontal velocity occurs almost at the same place;2)For a concrete dam type,the maximum value of turbulence intensity occurs almost at the same place under the same unit discharge condition when the relative water depth changes;3)Compared with traditional embankment which is composed of riprap and armor block,embankment structures with better permeability can be more beneficial for the stability,because the maximum value of the near-bottom turbulence intensity is farther away from the dam axis which makes the local scour hole further away.