Leakage-proof and high-safety pre-filled injector

The invention discloses a leakage-proof and high-safety pre-filled injector. An annular liquid medicine containing groove and an annular groove are formed at the positions, between a sleeve and a needle tube, of the hole wall of a blind hole, the annular groove is formed below the annular liquid medicine containing groove, and the top surface of the annular groove is in butt joint with the lower inclined surface of the annular liquid medicine containing groove, and an inclined block is fixedly arranged on the bottom surface of the blind hole; an annular ring is fixedly arranged on the cylindrical surface of a fixing base, the upper end of the sleeve is sleeved with a torsional spring located above the annular ring, and a lower through hole is formed in a lower supporting foot of the torsional spring; an upper through hole is formed in an upper supporting foot of the torsional spring, a stand column is fixedly arranged on the top surface of the annular ring, and a hook is fixedly arranged on the top surface of