This paper summarizes the research progress of friction stir additive manufacturing (FSAM) technology at home and abroad. FSAM is fast-forming, has high additive efficiency, and provides environmental protection. In addition, as a solid-phase additive technology, it effectively avoids shrinkage, porosity, and other defects caused by other melt-additive methods during molding. Currently, reported FSAM methods can be roughly divided into four categories: axial additive manufacturing, radial additive manufacturing, consumable friction-stir tool additive manufacturing, and superimposed plate additive manufacturing. The microstructures and properties of friction stir, laser, and arc additive samples are listed in detail. The advantages and disadvantages of the different additive methods and their application fields are expounded. The companies of friction stir additive equipment, the preliminary applications, and the development direction of friction stir additive equipment designed in the future are introduced. It lays a foundation for further application of friction stir additive technology.