Abstract: Three-dimensional mathematical model of scour around Trawl Resistant Seabed Basement on sand bed was established using Flow-3D. By changing the flow velocity and sediment particle size, the scour on sand bed under different conditions was simulated, and the changes in the trend of maximum scour depth around Trawl Resistant Seabed Basement with the two factors was analyzed. The results show that the scour depth around Trawl Resistant Seabed Basement is increased with current velocity increases, under the other setting conditions unchanged, the scour pit deepened velocity with increasing flow velocity is gradually slowed down, and ultimately achieved sedimentation balance. At the same time, due to the complex and changeable seabed environment, the model and the actual situation are different, and therefore further research should be continued.

Key words: Trawl Resistant Seabed Basement, sediment scour, numerical simulation