Abstract: The suspension and mixing characteristics of high-content solid particles were experimentally studied in a tank stirred with an Intermig impeller.An optical fiber technology was adopted to measure the bottom and axial solid concentration under different conditions of impeller diameter,rotational speed and impeller-bottom distance,and the critical suspension speed and power consumption were also investigated at the same time.The results show that the Intermig impeller has good axial mixing performance in the solid-liquid stirred system with high solid content.High impeller diameter and low impeller-bottom distance could improve the solid suspension and uniform distribution with low power consumption.By analyzing and fitting the experimental results,the bottom solid uniformity is calculated by Froude number with the equation of Q=0.58Fr^-0.35 and the power number is calculated by Reynolds number with the equation of N_P=2.1Re^-0.2.