Abstract: Aiming at exploring the effect of rotating stall on unsteady flow of solid-liquid two-phase centrifugal pump,this paper uses threedimensional numerical simulation by Mixture multiphase flow model under four flow conditions of 0.25Q_d～0.4Q_d,and analyzes head-efficien‐cy curve,internal liquid velocity distribution,solid volume fraction distribution and pressure pulsation characteristics are analyzed and cal‐culated. The results show that under the condition of C_V = 1%,the centrifugal pump head increases slightly and the efficiency decreases obvi‐ously as the flow rate decreases and enters the rotating stall condition. The rotating stall has a great influence on the flow field inside the cen‐trifugal pump. The liquid flow rate in each passage of the centrifugal pump decreases,and the solid particles are concentrated on the back of the blade. When the flow rate decreases to 0.25Q_d,the fluctuation of pressure pulsation is significantly more than that of other flow condi‐tions. The stall vortex caused by rotating stall has a great influence on the pressure pulsation of the centrifugal pump. Due to the influence of stall vortex,the pressure pulsation waveform at the impeller outlet is chaotic,and the amplitude of pressure pulsation increases with the de‐crease in the flow rate.