Preloaded medicine injector protection device

The utility model discloses a preloaded medicine injector protection device which comprises an outer sleeve and an inner sleeve, two opposite groove bodies are arranged on the outer sleeve in a penetrating mode, convex blocks are formed between the groove bodies and the outer sleeve, the upper ends of the two convex blocks are arranged close to each other, the outer sleeve is integrally arranged in a reducing mode, the inner sleeve is arranged on the outer sleeve, and the inner sleeve is arranged on the outer sleeve. The outer wall of the inner sleeve is fixedly connected with a first convex ring and a second convex ring which are arranged in an arc shape, the outer diameter of the first convex ring is smaller than that of the second convex ring, and the first convex ring is located above the second convex ring. After a syringe is used, the inner sleeve can partially slide out of the outer sleeve by pushing the syringe conveniently, a syringe needle can be shaded through the inner sleeve, and the second conve