Additive manufacturing, which is regarded as an accelerator and a key foundational technology supporting the innovative development of manufacturing, has been widely used in aerospace, automotive, healthcare, and other industries. To meet the development needs of weapons for high-performance, low-cost and rapid manufacturing, and agile maintenance at combat zones, et al, it is believed that additive manufacturing will have broad application space in weapons manufacturing. This paper summarizes the characteristics of different additive manufacturing processes and also introduces the current application status of additive manufacturing in weapons. By analyzing the technical research hotspots and the existing pain points in current applications in weapons of additive manufacturing, the development trends of additive manufacturing in weapons are predicted. Finally, some suggestions are proposed to accelerate the standardized application of additive manufacturing in the weapon industry.