[Objective] This paper focuses on the innovative applications of additive manufacturing (3D printing) in the field of electric motors, aiming to provide theoretical support and practical references for the development of high-performance motors. [Methods] Firstly, the additive manufacturing technology is elaborated from aspects such as industry background, process principles, technical systems, and competitive advantages. Then, its innovative applications in key motor components, including stators, rotors, permanent magnets, windings, and cooling structures, are systematically reviewed to clarify its cutting-edge development directions. Finally, the trends and current challenges of additive manufacturing in motor manufacturing are deeply analyzed. [Results] By 2023, the global 3D printing market value has exceeded $15 billion, with a compound annual growth rate of over 20%. In recent years, researchers have analyzed the materials adaptability such as high-temperature alloys, composite magnetic powders, and conductive polymers using mainstream processes like laser powder bed fusion and binder jetting, while identifying technical bottlenecks in precision, surface roughness, and post-heat treatment. [Conclusion] Additive manufacturing technology, with its unique layer-by-layer deposition principle and design freedom, has brought comprehensive transformations to the motor field, ranging from material preparation to system integration.