The emergence of insulin needle-free injection system is an epoch-making revolution in the field of injection system, replacing the traditional needle syringe, safe and painless, preventing infection, easy to use, simple and fast. The principle is to make the liquid drug through a very thin hole through high pressure, produce a liquid column, penetrate the skin to spray under the skin, so that the absorption effect is greatly improved. Widely used in the injection of insulin, interferon, vaccines and other small amounts of liquid drugs.