Abstract: Based on the finite volume method and unstructured triangular mesh, a depth-averaged 2D mathematical model for dam-break flows on erodible beds has been developed by coupling the shallow water equations, sediment transport equation, and bed evolution equation. This model adopts the momentum and continuity equations for turbid water considering vegetation effects, sediment transport and morphological changes, and uses a Roe solver and approximate Riemann solutions to calculate the grid face fluxes, which is able to capture dry-wet moving fronts with second-order accuracy. The hydrostatic pressure and the vegetation resistance are put into the source term of momentum equation. The model was verified against four cases of the laboratory measurements documented in the literature, and the calculations agree well with the measurements. The verification shows that the model is able to simulate the evolvement of dam-break flows and the deformation of bed morphology on a complex computational domain with good accuracy. Simulations of the vegetation cases show that the vegetation on a shoal can reduces the velocity of dam-break flows and the erosion on the downstream bed but it also reduces the local flood discharge capacity, which leads to a certain rise in the upstream water level.