Abstract: Additive manufacturing, as an important part of Industry 4.0, has attracted great attention in recent decades. Friction stir additive manufacturing (FSAM) is a new solid-state additive manufacturing technique derived from friction stir welding. This technique provides a new approach for the high-performance and rapid preparation of lightweight alloy components such as aluminum alloys and magnesium alloys, due to advantages of no solidification defects, small grain size, and low residual stress. Based on industrial application of FSAM, principles and characteristics of FSAM are introduced. Research progress of microstructure characteristics and mechanical behavior of aluminum alloy FSAM components are reviewed. Development status of its extended applications is summarized. Finally, future research directions of FSAM technique are discussed, which provides useful references for its development and application.