Numerically predicting erosive wear in dredging pumps is an important research aspect. Strong interactions between discrete particles and continuous water increase the complexity of the flow. The sand-water flow in a continuous elbow and the associated influencing factors, such as turbulence model, near-wall treatment, wall roughness, and volume fraction of sand, were simulated, and then the results were compared. Based on the comparison results, a problem-solving strategy is presented, in which water with small sand particles is assumed as a type of homogeneous Newtonian fluid and only the effect of large sand particles is considered. This strategy is used to predict the slurry flow and erosive wear in the impeller of a dredging pump DRC257-900. The result is compared with that of an actual dredging pump impeller. It is found that the strategy with two-way coupling can accurately predict the location of erosive wear in the impeller with low computational costs.