<p>By using the phased characteristics summarizing method of the existing research on magnesium slag, this study investigates the hydration reaction, alkali activation reaction and CO₂ mineralization reaction processes and mechanisms, and then explores its high-value utilization. The results show that physical and chemical activation can improve the mechanical properties of the gelled material system by increasing the crystal phase defects and surface energy and by reconstructing a new gelling system by depolymerizing glass. The CO₂ mineralization reaction of magnesium slag can be used to construct a new gelling system for CaCO₃ and calcium-modified silica gel. Magnesium slag can also be used to enhance the dry shrinkage and carbonation resistance of concrete owing to its expansibility and high alkali reserves. The mechanism and existence form of heavy metal ions in magnesium slag have been clarified. The study proposed a production system for magnesium slag and highlighted the potential research value in the field of wet carbonation to promote the application of magnesium slag.</p>