Based on the Eulerian-Lagrangian method, a three-dimensional numerical model has been developed by using the modified k-ε parameterization for the turbulence in fluid phase and Lagrangian method for the solid phase. The model has been verified by using measured variation of diffusion properties of sediment particle cloud in the water, such as the vertical frontal position Zf, longitudinal width Lf and longitudinal frontal position Xf. Finally, the variation of the turbulent kinetic energy of sediment particle clouds during the diffusion process in the water is studied by using this verified model. The numerical results show that the turbulent kinetic energy of sediment particle cloud is affected by the speed of cross-flow velocity, the size of initial volume of sediment cloud and the difficult particle size.