<p>HIsmelt process has the potential to directly smelt chromium ore powder, but the CaO–SiO₂–MgO–Al₂O₃–FeO–Cr₂O₃ slag obtained by smelting is unique, and the viscosity characteristics of the slag system are not clear. Therefore, the viscosity and structure of HIsmelt chromium-containing slag were studied in this paper. The results of viscosity experiments show that increasing the content of Cr₂O₃ will significantly increase the viscosity of slag. The suitable slag basicity is 1.2, the ratio of MgO/Al₂O₃ is 0.8, and the content of FeO is 4&#xa0;pct. The results of Raman spectroscopy show that the addition of Cr₂O₃ promotes the transformation of low polymerization unit to high polymerization unit, and the degree of polymerization of slag increases, resulting in an increase in viscosity. The addition of MgO shows the opposite effect. The results of molecular dynamics simulation show that with the increase of Cr₂O₃ content, the proportion of bridging oxygen increases from 64.85&#xa0; to 71.73&#xa0;pct, and the proportion of non-bridging oxygen decreases from 31.98 to 25.55&#xa0;pct. With the increase of MgO/Al₂O₃, the proportion of bridging oxygen decreased from 66.03 to 62.13&#xa0;pct, and the proportion of non-bridging oxygen increased from 31.15 to 34.53&#xa0;pct. Cr³⁺ are network builders, bridging more O^2- and occupying tetrahedral positions, making the silicate network structure more complex, and Mg²⁺ can depolymerize the silicate network.</p>