As an important part of aero engine, blade damage and maintenance have an important impact on aircraft operation safety and operating cost. To improve the maintenance quality and efficiency, scholars at home and abroad have carried out considerable theoretical and technological research on blade maintenance. To further analyze the maintenance process of damaged blades, firstly, the damage types and causes of fan blades, compressor blades, turbine blades and integral disk blades were summarized, and the maintenance technical routes under different damage conditions were analyzed in detail. The research field of in situ maintenance is weak. Therefore, the related technology and equipment of in situ maintenance are explained in detail, as well as the related optimization method and the application of new technology. Finally, the research and development direction of aero engine blade maintenance are prospected, which can provide reference for future researchers in this field.