A safe detained needle is disclosed. The safe detained needle of the present invention comprises a detained trocar, a trocar seat, a puncture needle, a protective seat, and a needle seat. The protective seat comprises a through hole, a rebound unit, and a sticking plate. When the puncture needle is withdrawn from the detained trocar and the trocar seat, the tip of the puncture needle is restricted in the protective scat by the rebound unit and the sticking plate for preventing the tip of the puncture form being exposed outside.
