Additive friction stir deposition （AFSD） technology， as an emerging additive manufacturing method， has attracted widespread attentions in the field of materials science and engineering in recent years. This study summarizes the results of research on the evolution of material temperature， plastic flow and microstructural changes during the additive process from the perspective of AFSD forming mechanisms. The influence of additive passes and process parameters on the mechanical properties of AFSD additive parts is discussed in depth. The domestic and international development progresses of AFSD additive tools and equipments are introduced in detail， which provide new ideas for the application prospects and development directions of AFSD.