Automatic injection assistor

The utility model relates to an automatic injection assistor which comprises a sleeve cylinder and a pushing cylinder which is movably pulled, pushed and sheathed with the sleeve cylinder, wherein a needle outlet hole is arranged on the sleeve cylinder and a sheath is inserted and connected to the needle outlet hole. A return spring is arranged between the sleeve cylinder and the pushing cylinder. An elastic limit block matched with a clamping opening on the sleeve cylinder is arranged on the outer wall of the pushing cylinder. A pushing button matched with the elastic limit block is fixed on the outer wall of the sleeve cylinder. The end part of the pushing cylinder is provided with a set nut of a needle cylinder. The utility model overcomes the defects that the medicine injection needs operating by other persons, the patients' pain is large, and the operation is bothersome existing in the prior art. Because of the design, the injection can be operated by the patients, the accuracy of injection positions is high, and the patients' pain is relatively little. The utility model has the advantages of simple structure, convenient operation and safe use.