Injector capable of eliminating residual pressure

The present invention relates to a syringe capable of eliminating residual pressure, comprising: a barrel (110) filled with a medicinal material and having a medicinal liquid discharge hole (113c) formed at one end thereof; a piston (120) which is inserted into the cylinder (110), moves forward by receiving pressure, discharges the liquid medicine through the liquid medicine discharge hole (113c), and protrudes from a front pressurizing plate (121) toward the liquid medicine discharge hole (113c) to form a coupling shaft (122) having a predetermined length; a seal ring coupling ring (130) coupled to the rear end of the coupling shaft (122); and a residual pressure eliminating seal ring (140) which is coupled to the seal ring coupling ring (130) so as to surround the coupling shaft (122) in the front, and which, when the pressure applied to the piston (120) is released, eliminates the internal residual pressure to prevent additional leakage of the chemical liquid. The seal ring coupling ring (130) is coupled t