Based on the Euler two-fluid model，the unsteady numerical simulation of solid-liquid two-phase flow of large dredging pump of cutter suction dredger is carried out.Through the analysis of the effects of particle size，particle concentration and particle density on the flow field characteristics of dredging pump including the two-phase streamline and solid particle concentration distribution，it provides guidance for improving the optimal design of dredging pump.The simulation results show that the physical properties of particles have little effect on the streamline distribution of liquid phase，and the driving effect of liquid relative to solid phase decreases with the increase of particle size.With the increase of particle density，the driving effect of liquid relative to solid does not weaken.With the increase of particle concentration，the driving effect of liquid relative to solid phase increases.With the increase of particle size and density，the uneven distribution of particles increases.With the increase of particle concentration，the uniformity of particle concentration distribution strengthened，and the concentration near the blade wall increased significantly.By comparing the particle concentration distribution of the two dredging pumps，the reasonable design of the impeller channel can reduce the agglomeration of particles on the surface of the channel and the abrasion of the dredging pump.