Bone marrow mesenchymal stem cells (MSCs) are multipotent stem cells with the ability to differentiate into bone-producing cells, which is essential for bone formation. Magnesium biomedical materials, such as biodegradable matters with osteoinductive properties, play a vital role in the osteogenic differentiation of MSCs. International and Chinese studies have shown that magnesium ions, which are produced by biodegradation, mainly achieve this effect by regulating the expression of genes and proteins associated with osteogenesis, activating multiple signal pathways, elevating autophagic activities, and adjusting the pH in the microenvironment. It is of great significance to study the regulatory mechanisms and identify the optimal conditions that how magnesium ions promote osteogenic differentiation of MSCs. In this study, we summarized the regulatory mechanisms noted above.