Special nozzle for needleless injector

The utility model relates to a special nozzle for a needleless injector. The nozzle comprises a nozzle main body (1) and an irregular space ring (2) applicable to the nozzle, wherein the nozzle main body (1) consists of a spray head (3) and a conical rear end part (4); the conical rear end part (4) is gradually narrowed toward the small-diameter spray head (3); the irregular space ring (2) is arranged on the spray head (3) and is matched with the spray head (3); an annular groove (6) is formed in the top end of the conical rear end part (4); a stop device is arranged on the inner wall of the annular groove (6). The stop device is destroyed after being used once, so that secondary use is prevented to avoid cross infection.