Vacuum Degassing (VD) is a crucial secondary refining process for high-quality steel manufacturing, which is applied to remove hydrogen, nitrogen, carbon, oxygen and inclusions in molten steel under vacuum atmosphere. However, the whole refining process in practical production is commonly referred on the artificial experience, and the field information inside the reactor is not clear yet. Therefore, a two-phase Eulerian model with considering degassing dynamic has been developed to investigate the flow field and degassing rate in a full-scale industrial vacuum degasser. Meanwhile, the model is verified by physical water modeling and industrial Riva production data, which shows that the computational results of the present model are well consistent with the measurements. The model includes three possible dehydrogenation sites, the surface of argon bubbles, the free surface of the molten steel, and the bulk steel near the bath surface. The results indicate that with the vacuum pressure increases, the removal ratio of hydrogen decreases. However, the endpoint of the dehydrogenation reaction is independent of the initial hydrogen content. Increasing the argon flow rate enhances the processing efficiency, but the excessively high flow rate exacerbates the erosion of refractory materials. For the dehydrogenation efficiency, the bubble surface contributes the most removal, following by steel free surface, and little by bulk steel near the bath surface.

CFD，VD，脱氢， 反应位点，钢液