Pneumatic energy storage type needleless injector

The utility model discloses a pneumatic energy storage type needleless injector. The needleless injector comprises a cylinder barrel, a front end cover, a needleless ampoule assembly, an impact piece and an air supply device, wherein the cylinder barrel is provided with an inner cavity, the front end cover is fixedly arranged at the front end of the cylinder barrel, the needleless ampoule assembly is installed on the front end cover, the impact piece is arranged in the cylinder barrel in a front-and-back movable manner, a closed chamber is formed between the impact piece and the back part of the cylinder barrel, the air supply device is used for feeding compressed air into the chamber, and the needleless ampoule assembly at least comprises a piston rod capable of moving forwards and backwards; the impact piece has an energy storage state and an impact state in the cylinder barrel; when the impact piece is in the energy storage state, the impact piece is static, an interval exists between the front end of the impact piece and the back end of the piston rod, and the air supply device feeds the compressed air into the chamber; when the impact piece is in the impact state, the impact piece impacts forwards and drives the piston rod to move forwards; and a control mechanism for switching working states of the impact piece is also arranged on the cylinder barrel. The needleless injector is simple and compact in structure and good in usability.