A pneumatic accumulating needleless syringe comprising a barrel (11) provided with an inner cavity, a front end cap (12) fixedly arranged at the front end of the barrel, a needleless ampoule component (15) mounted on the front end cap, and an impact element (13) arranged within the barrel and movable in the forward and rearward directions. A closed first chamber (113) is formed between the impact element and the rear part of the barrel. The needleless syringe also comprises an air supplying apparatus used for inflating a compressed gas into the chamber. The needleless ampoule component at least comprises a plunger (151) movable in the forward and rearward directions. The impact element is provided with an accumulating state and an impacting state in the barrel. When the impact element is in the accumulating state, the impact element is stationary, a gap is found between the front extremity of the impact element and the rear extremity of the plunger, and the air supplying apparatus inflates the chamber with the compressed air when the impact element is in the impacting state, the impact element impacts forward and drives the plunger into a forward movement. A control mechanism (14) used for switching the work states of the impact element is also arranged on the barrel. The needleless syringe is structurally simple and compact and provides great use performance.Cet injecteur sans aiguille à accumulateur pneumatique comprend un cylindre creux (11), un couvercle dextrémité avant (12) fixé sur lextrémité avant dun cylindre, un ensemble ampoule sans aiguille (15), une armature dimpact (13) logée mobile dans un cylindre le long de celui-ci, une première chambre vide (113) formée hermétiquement entre la pièce dimpact et la partie arrière du cylindre, ainsi quun dispositif dalimentation en air destiné à remplir la chambre dair comprimé. Lensemble ampoule sans aiguille comprend au moins une tige de piston (151) se déplaçant davant en arrière, la pièce dimpact logée dans le cy
