Supersonic flame spraying (HVOF) is a new thermal spraying technology developed in the early 1980s on the basis of ordinary flame spraying. It is the use of hydrogen and acetylene, propylene, kerosene as fuel, such as using oxygen as accelerant, burning in the combustion chamber or special nozzle, produce up to 2000 ~ 3000 ℃, more than 2100 m/s speed of supersonic combustion flame, and at the same time to send powder to a flame, molten or semi-molten particles, high speed impact formed on a substrate surface deposition coating, the preparation of supersonic flame than ordinary flame spraying and plasma spraying coating preparation of coating bonding strength higher and more dense.