Abstract: The problem of high concentration solid-liquid two-phase flow is difficult to overcome because the flow is complex in the vortex grit chamber. It leads to poor engineering design and operation. Eulerian - Eulerian solid-liquid two-phase flow model with the consideration of collision between particles is presented in this paper. The model is gained from the perspective of microscopic interaction between liquid and solid through the molecular kinetic theory and the computational fluid dynamics. Sliding mesh technology is used to simulate the vortex grit chamber in a hydropower sandstone wastewater treatment, Southwest China. The influences of the four factors including rotate speed, distance between the propeller and the base, number of propeller blades and angle of the propeller on the efficiency of the grit removal efficiency are studied. According to the single factor test, the optimal condition for the novel vortex grit chamber is that, the rotate speed of propeller is 105 rap/min, the distance between the propeller and the base is 592mm, the number of propeller blades is 4 and the angle of the propeller is 45?