A safety syringe includes a syringe and a safety needle, wherein the safety needle comprises a needle seat, an injection needle, a needle sleeve and an elastic part.The injection needle is connected with the needle seat, the needle sleeve is connected with the needle seat in a detachable way and is sleeved on the injection needle； the elastic part is arranged between the needle seat and the needle sleeve, one end of the elastic part is connected with the needle seat and the other end is connected with the needle sleeve.When the needle sleeve is combined with the needle seat, the elastic part is compressed. When the needle seat is separated from the needle sleeve, the elastic part recovers and pushes the needle sleeve in the direction of the needle tip of the injection needle, so that the needle sleeve covers the needle tip.Thus, the tip of the needle is not exposed.一種安全注射器，包含有一注射筒與一安全針頭，其中，該安全針頭包括一針座、一注射針、一針套與一彈性件。該注射針結合於該針座，該針套以可分離的方式結合於該針座且套於該注射針上；該彈性件設置於該針座與該針套之間，該彈性件的一端連接該針座，另一端連接該針套。當該針套與該針座結合時，該彈性件受壓縮，當該針座與該針套分離時，該彈性件彈力回復，將該針套往該注射針之針尖的方向推動，使該針套遮蔽該針尖。藉此，避免針尖裸露。
