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Additive manufacturing technology is a rapid prototyping technology that has developed rapidly in recent years. It is widely used due to its many advantages, such as short manufacturing cycle, low cost, and the ability to manufacture complex parts. This article introduces the classification of additive manufacturing and the characteristics of the metallurgical structure. The special super-normal metallurgical process of the additive manufacturing process leads to the existence of (1) significant coarse columnar crystals in the metallurgical structure of titanium alloys, and with the change of manufacturing methods, the size of the columnar crystals occurs Change; (2) There is an uneven distribution of the structure, including the uneven distribution of phase and grain size. Focusing on the metallurgical structure of additive manufacturing, the method to improve the metallurgical structure is systematically explained, including changing process parameters, external field assistance, such as magnetic field, ultrasonic field, online rolling plastic deformation, adding nucleating agent to refine grains, etc. The systematic elaboration of the thesis will provide a reference for the improvement of additive manufacturing organization in the future.