Syringe needle protection device and safety syringe thereof

The utility model relates to a syringe needle protection device and a safety syringe thereof. The syringe needle protection device comprises a protection outer sleeve, an installation inner sleeve and a spring. The outer side of the mounting inner sleeve is sleeved with the spring, and then the mounting inner sleeve is pressed in the protective outer sleeve; the outer surface of an outer sleeve cylinder of the protective jacket is not provided with a bulge structure; a concave inner spigot is formed in the middle of the inner side wall surface of an outer sleeve cylinder of the protective jacket; a retaining claw is arranged at the bottom of the mounting inner sleeve; and the retaining claw is bounced off after the installation inner sleeve and the protection outer sleeve are excited, and is clamped above the inner spigot. The safety injector comprises an injector body. The syringe is installed in the installation inner sleeve of the syringe needle protection device. According to the utility model, the relate