Abstract: Rust cleaning and painting of metal tanks, especially the large-scale tanks installed in caves is hard to do. There are many disadvantages such as obsolete equipment, backward techniques, low efficiency and poor quality, high cost, harmful to human and long working cycle. All the above problems have been well solved with the development of rust cleaning and painting machine by the Air Force Logistics Institute of the PLA. The machine can improve work efficiency and reduce cost by using the three-phase abrasive material (gas-liquid-solid) to clean rust and painting with non-air high pressure. In the paper, the structure and working principles of the machine as well as its characteristics and operation are introduced.