The present study investigates how solids affect the hydrodynamic characteristics in gas-liquid-solid flow in a cubic tank with a flat square base (length T = 230 mm) using two-dimensional particle image velocimetry (PIV). The fluid was stirred by a half elliptical disk turbine (HEDT) of diameter D = 77 mm. Flow fields at three different gas holdups (maximum 3.73%) were investigated, with the particle volumetric fraction up to 1.6%. The results show that the particles have a more significant in fluence on turbulent flow in solid-liquid two-phase flow and three-phase flow with 1.42% gas holdup than in the three-phase flow with 3.73% gas holdup. In multi-phase flow, the velocity of continuous phase is greatly influenced by the concentration of dispersed phase, but is rarely influenced by its density. However, the turbulent kinetic energy is affected by both of them.