<p>The structural changes in the CaO–SiO₂–Al₂O₃–MgO slag system with varying CaO contents were investigated through molecular dynamics (MD) simulations, and its effect on the dissolution behavior of alumina inclusions was characterized by the Kullback–Leibler (KL) divergence. The slag structure analysis revealed that the [AlO] tetrahedral structure was the primary network structure in the slag. With increasing the CaO content, the non-bridge oxygen (NBO) content in the slag structure increases, and the bridge oxygen (BO) content decreases, thereby reducing the complexity of the slag network structure. Raman spectroscopy detection verifies the results of the MD simulations. The results indicated that the dissolution rate of alumina inclusions accelerates with increasing the CaO content in the slag, owing to the reduced complexity of the slag network structure and the enhanced interatomic interactions. The simulation results for the dissolution of alumina inclusions were consistent with theoretical calculations based on the slag inclusion capacity and the dimensionless dissolution rate of inclusions. Radial distribution function analysis demonstrated that the interaction between atoms in the slag system and alumina inclusions strengthens, increasing the dissolution rate of alumina inclusions. The [AlO₆] octahedral structure of the alumina inclusions is disrupted, forming BO structures, which in turn enhances the complexity of the slag network structure, slowing the dissolution rate of alumina inclusions. In contrast, the slag system with a higher CaO content has a relatively simpler network structure, promoting faster alumina inclusion dissolution.</p>