In order to improve the reliability and service life of military equipment, the application of additive manufacturing technology in the repair of key components of military equipment was studied. Additive manufacturing technologies such as selective laser melting (SLM), electron beam melting (EBM) and laser melting deposition are analyzed, and different additive manufacturing processes and their application examples in different parts repair scenarios are introduced. The results show that additive manufacturing technology can not only effectively repair and strengthen key components of military equipment, but also significantly improve the mechanical performance and service reliability of equipment by optimizing process parameters. It provides support for the maintenance and upgrading of military equipment, and has broad application prospects.