The paper is dedicated to analysis the inclusion behavior in steel using theoretical calculation and simulation of water. The aim is to establish collision and absorption model of inclusions on refractory. The article discusses the variation of critical stay speed and critical shear with the radius of inclusions in the process of colliding, rebounding and absorbing. The results show the critical stay speed and critical shear of alumina respectively surpasses 1 cm·s−1 and 1 N·m−2, while titanium dioxide separately exceeds 4 cm·s−1 and 10 N·m−2 for the inclusions that radius is less than 2.5 μm. If the inclusions occur rebound after colliding, the inclusions that radius is less than 7 μm will still be absorbed by the surface, while the inclusions that radius is more than 10 μm can easily reenter the steel. The model coincides with the water simulation results and it is of good adaptability.