"Micro-complex in-tube Coating" is the world's first micro-complex fuel pipe coating technology used in satellite propulsion systems. It is the only one that can target micro-slender features with an inner diameter of only 4 mm. Curved pipes and other 3D complex geometric shapes of pipes form a highly uniform, complete and dense nanometer-level coating protective layer. For applications in the space industry, especially in the multi-channel slender fuel stainless steel pipe fittings of satellite orbit change systems, the development can improve the compatibility with fuel and promote the localization of crucial satellite components. Recently, the development has been initially applied to the aerospace satellite industry and gradually expanded to the semiconductor and medical industries.The development has assisted the Taiwan Space Agency (TASA) in cooperating with research projects for the third consecutive year.