The molybdenum alloy has received more and more attention in various industrial fields, but its extensive applications are restricted due to the degradation of its creep resistance, strength, and oxidation resistance at high temperature, and the lack of effective mass production methods. This research analyzes the brittleness source of pure molybdenum, and reveals that the improvement of extrinsic brittleness and innovation of preparation process are the key directions of research and development of molybdenum alloys. The methods applied for strengthening and toughening of molybdenum alloys are reviewed, and the research and application status of typical molybdenum alloys are listed. In addition, in consideration of the existing problems, the research direction of high temperature molybdenum alloys is summarized.