The invention discloses a
back pressure type medical
bottle and a
composite element of a dispensing device and an
injection device of the back type pressure medical
bottle. The
back pressure type medical
bottle comprises a bottle body with a straight
barrel type inner wall, a first
piston is arranged at the position, close to a bottle opening, in the bottle body, a
blind hole is formed in the center of the outer bottom face of the first
piston, and outer edge and a sealing cover are arranged on the bottle opening, wherein the sealing cover is fixed to the outer edge and used for preventing the first
piston from falling off. For the other situation, the
back pressure type medical bottle further comprises a second piston arranged in the middle of the bottle body, a pushing plate is arranged in second piston in a covered mode, and a
needle guide hole is formed in the center of the push plate. The back pressure type medical bottle in cooperation with the dispensing device and the
injection device of the back type pressure medical bottle can systematically solve the problem of secondary
pollution in the dispensing process and the injecting process, and is not only suitable for being used in city hospitals, wide-range mountainous areas, countries and other places where sanitary conditions are poor, but also suitable for being used in the wild, warships, battlefields and disaster areas.