Porous magnesium alloys are receiving increasing attention from industry because of their porous structure, remarkable lightweight effects, excellent electromagnetic shielding performance, superior vibration damping, energy absorption and noise reduction properties, corrosion resistance surpassing that of bulk magnesium and outstanding biocompatibility. These attributes position porous magnesium alloys as materials with promising application potential in high-end industrial fields. This article reviews the current applications of porous magnesium alloys in aerospace, rail transportation, defense and military, biomedical, consumer electronics (3C), energy development, robotics, and unmanned aerial vehicles. A comprehensive overview of porous magnesium alloy fabrication technologies is provided, detailing the characteristics and research advancements of various preparation methods, along with their respective strengths and limitations. Finally, the future development direction of porous magnesium alloy preparation technology is discussed.