The utility model relates to a single hand operation pollution-free air needle, which comprises a needle cylinder and a needle center. The inner wall of the needle cylinder has a protruding edge, the needle center extends into the needle cylinder, the needle center includes a rod body and an elastic plug, the rod body has two side plates, the side plates are combined with a number of connecting parts, the upper side of the connecting part is not in contact with the inner wall of the needle cylinder, and the upper side of the connecting part is low from one side to the other side. The elastic plug comprises a groove, one side of which is provided with a guide part.In the case of dilution procedures in medical injection operations,The inner wall of the syringe is contacted by the guide part.Make the needle center in the needle cylinder for backward drawing.The press in process can be stable and not deviated.And the upper side of the connecting part of the needle center is not in contact with the inner wall of the needle cylinder.And the upper side of the connecting part is lower than the upper edge of the side plate from one side to the other.And keep the same distance with the upper edge of the side plate.Accordingly,When operating the empty needle with one hand,Even if the hands touch the joint of the needle center,It can also prevent the connection part of the needle center from contacting the inner wall of the needle cylinder.In order to avoid one-time pollution in the syringe,Easy to operate,CleanlinessHealth and other effects.The invention has the advantages of reducing the opportunity of using gloves, having good environmental protection and reducing the use cost, and preventing the infection of patients, especially the anti-cancer patients and the people with low immunity, avoiding the prolonged hospitalization due to the infection, thereby reducing the health insurance expenditure.一種單手操作無汙染空針，包含一針筒、一針心，該針筒內側壁具有一突緣，該針心伸入該針筒中，該針心包含一桿體、一彈性塞，該桿體具有二側板，該側板之間結合數連接部，
