Abstract:The inner wall coating technology is an effective method that can reduce the damage to the tube wall caused by the contents of the tube, and which can effectively improve the service life and service safety of the thin tube parts. In recent years, more and more attention has been paid to the preparation technology of the inner wall coating of slender tubes, and important progress has been made in both preparation technology and application. The development history and classification of internal wall coating technology applied at home and abroad are introduced systematically, with emphasis on the film formation of thin wall coatings prepared by hot dip plating, electroplating, physical vapor deposition, chemical vapor deposition, and micro-arc oxidation. The mechanism is discussed in details. Based on the development and application status of thin tube inner wall coating technology, the results and existing problems of existing research and applications are summarized from the aspects of theoretical research, use environment, and technical engineering application. The potential application prospects of the above technologies are analyzed and prospected mainly from the aspects of coating material system, substrate characteristics, thickness uniformity control, and interface bonding characteristics.