The invention discloses a treatment device for a medical
injector and a use method of the treatment device, and belongs to the field of medical injections. The treatment device can integrate a
piston assembly, a
medicine bottle and a needle head, when the
piston assembly moves downwards to conduct injection operation, liquid
medicine is injected into the body of a patient through
extrusion of a film on the
medicine bottle, so that it is guaranteed that the liquid medicine does not make contact with the external environment in the whole process of injection operation, and
pollution is avoided; meanwhile, when the injection operation is finished, through ordered conversion of space leakproofness and non-leakproofness in the
piston assembly, the film is driven to expand outwards, the medicine
bottle falls off from the position where the medicine bottle is clamped by the film currently, the clamping relation cannot be recovered, and the needle head is almost impossible to be aligned to the positions of an upper cover and a lower cover of the medicine bottle for the second time, so that the situation that the
injector is used for the second time is effectively avoided; and in the process of injection, mutual matching between
bandage sending out and
bandage receiving is adopted to prevent secondary use.