A rapid air-tightness test clamp of a needle-integrated injector comprises a pedestal, a lower press ring, an elastic O-shaped ring, an upper press ring and a fastening cover. The lower press ring, the elastic O-shaped ring and the upper press ring are sequentially stacked in a groove on the pedestal, and the fastening cover is connected with the screw thread in the groove of the pedestal througha fastening screw. The invention can seal the sheath of an injector to be tested by screwing the fastening screw to press the elastic O-shaped ring to deform, thus facilitating the air-tightness testof the needle-integrated injector. The invention has the advantages of convenient, rapid and safe usage, simple structure, easy manufacture, low cost and convenient generalization.