Injection needle apparatus with safe-protection function

An injection needle apparatus with safe-protection function, comprising:

• an injection module (1) including an injection cylinder and a pullable piston rod installed within the injection cylinder;
• the injection cylinder including a main body, a head portion and a handhold portion;
• the head portion and the handhold portion being at two ends of the main body, respectively;
• a needle module (2) including a needle seat and an injection needle;
• the needle seat having a seat body and a buckle;
• in installation state, the seat body covering the head portion and holding the injection needle;
• the buckle being integrally connected to the seat body at an end near the main body and around the seat body;
• a safety sleeve (3) covering movably around the injection cylinder (11) between an installation position and a protection position;
• the safety sleeve having a sleeve body, a first end portion, and a second end portion;
• the first end portion and the second end portion being at two opposite ends of the sleeve body;
• wherein in the installing position, the first end portion is near the buckle and the second end portion is near the handhold portion;
• while in the protection position, the first end portion is protruded from the injection cylinder for covering the injection needle and the second end portion is near the head portion;
• and
• an inner side of the sleeve body (31) near the second end portion being formed with a buckling portion;
• the buckling portion being used to buckle with the buckle (212) so that the safety sleeve (3) and the needle seat (21) are fixed together for separating from the injection cylinder and after separation, the safety sleeve covers the needle seat.