Pre-injection preparation injector provided with safety protection device and used for erythropoietin injection

The invention relates to the field of medical devices, in particular to a prefilled preparation of erythrotropin injection with a safety protection device. The present invention firstly provides a prefilled syringe with a safety protection device, including a safety protection device, the safety protection device includes an outer cylinder and a first inner cylinder sleeved in the outer cylinder, and the first inner cylinder is elastically The parts are movably sleeved outside the needle tube, the rear end of the outer cylinder is provided with a needle tube flange displacement limiting part, the first inner cylinder includes a needle protection part, and the outer wall of the first inner cylinder and the inner wall of the outer cylinder are provided with anti- The rear end of the first inner cylinder escapes from the first stop component of the outer barrel and the second stop component that blocks the front end of the first inner barrel from moving toward the needle. When the needle tube of the prefilled syringe is prefilled with erythropoietic liquid medicine, a prefilled preparation of erythropoietic injection with a safety protection device is formed. The invention can pop out after the injection is completed by setting the safety protection device, so as to protect the needle from injuring medical staff and patients.