Magnesium and its alloys, as the metal materials with the lowest density among structural materials, have attracted much attention due to their excellent properties such as high specific stiffness, good electromagnetic shielding properties and good vibration damping effects. However, its low strength, inherent brittleness and poor corrosion resistance limit its application in various industries. By adding a reinforcing phase to the magnesium matrix, a magnesium-based composite material having excellent properties has become one of the effective ways to realise the industrial application of magnesium alloys. This article reviews the recent research progress of magnesium-based composites, including the reinforcing phases and preparation methods of magnesium-based composites, and looks forward to the future development and research directions of magnesium-based composites.