Abstract: The current status and development trends of additive manufacturing (AM) technology for large-size metal components are reviewed with applications in aerospace, energy, and other fields. Firstly, the basic principles of AM and its advantages and limitations for large-size metal components are discussed. Secondly, research progress in process parameter optimization and intelligent control technologies during AM is analyzed. Particular focus is placed on the application of external field-assisted control, real-time monitoring, and adaptive control technologies to enhance the precision and stability of the manufacturing process. Additionally, online and post-processing shape synchronization control technologies for large-size metal components are emphasized. Combined with heat treatment and machining methods, these technologies are shown to effectively improve forming quality and mechanical properties. Finally, future prospects of AM technology for large-size metal components are outlined, and key issues related to process optimization, material properties, production efficiency, and sustainable development are identified. The review demonstrates that with continuous technological advancements, AM is expected to find broader applications in various fields and contribute to the transformation of traditional manufacturing models.