The present invention relates to a disposable syringe and specifically to a smart safety syringe capable of fundamentally blocking secondary infections due to needle stick injuries at the time of injection to a patient and secondary infections due to needle stick injuries when collecting discarded or disused syringes for reuse although those discarded or disused syringes must be disposed after one use. The present invention comprises an outer container comprising an external locking key formed to protrude at an inner peripheral edge of a front-end portion, an outer container tip formed inside the external locking key, and an inner locked wall extended in a radial direction from a base end of the external container in the rear of the external locking key and connected to an inner circumferential surface of the front-end portion； an external needle hub configured to be fitted to the outer container tip at the front of the outer container, wherein a protrusion formed at the base end is caught between the external locking key and the inner locked wall to block a forward and backward withdrawal； an inner needle hub configured to be inserted from the rear of the outer needle hub and fitted to be bound to an inner side of the external needle hub, wherein a needle protruding forward by penetrating the front-end portion of the external needle hub and a push-lock key is protruded on the inside； a needle cap configured to cover the external needle hub with the needle； and a push stick configured to be inserted from the rear of the external container wherein a push-lock hook formed at the front end is caught by the push-lock key upon insertion to the inner needle hub.본 발명은 일회용 주사기로서 환자에 주사 시 바늘찔림(Needle stick injury) 사고로 인한 2차감염 및 일반적으로 1회 사용 후 폐기되어야 함에도 재사용하는 폐단 및 폐기된 주사기를 수거 시 바늘찔림으로 인한 2차감염을 원천적으로 차단시켜 줄 수 있는 스마트 안전 주사기에 관한 것이다. 본 발명은, 전단부 내주연에 돌출 형성되는 외부잠김키와, 상기 외부잠김키의 내측에 형성되는 외통팁과, 상기 외부잠금키의 후방에서 상기 외통팁의 기단부로부터 반경방향으로 연장되어 상기 전단부의 내주면으로 이어지는 내부잠김벽을 갖는 외통과； 상기 외통의 전방에서 상기
