Magnesium alloy is internationally recognized as one of the most potential lightweight materials. It is known as the “green engineering metal of the 21st century”， and its outstanding structure weight reduction effect is expected to solve the urgent lightweight problems of key equipment and major projects in China. In this paper， the development of new magnesium alloys， the progress of new preparation and processing technologies of magnesium alloys， and the applications of magnesium alloys in recent years are reviewed， and the shortcomings in the current magnesium alloy field are summarized. Finally， the development focus and main tasks of magnesium alloys in the future are prospected.