In order to study solid-liquid 3-D two-phase turbulent flow in a pump, the SIMPLEC algorithm was used with the casing to calculate the coupling question of a centrifugal impeller based on N-S equations and the standard two equations k-ε turbulent model. From the computed information, the distribution of solid particles of different particle sizes and different volume fractions, at off-design conditions and different specific gravities were obtained, and the characteristic of pump was also calculated. The results indicated that specific gravity and particle diameter, which are the nature of particles, had more influence on the distribution of solid particles. Particles with large specific gravity value and diameter were easy to trend to working face by the effect of inertia force. The volume fraction also had an effect in particle distribution; because of relative flow angle changing in off-design conditions, particles had different distribution and movement laws. Increasing specific gravity, particle size and solidphase volume would cause the reduction of head.