The present invention relates to a self-destructive insulin syringe, which comprises a barrel, a plunger, a rubber plug, and a needle holder, and is characterized in that the barrel is configured with a coupling needle holder. The coupling needle holder is supported and fixed at the front end of the barrel by a support base. The needle holder is formed with a retaining ring by extending downwardly. The upper end of the coupling needle holder is formed with an engaging ring, in which the engaging ring is extended into the inner hole of the retaining ring and engaged with the engaging ring. The wall of the inner hole of the coupling needle holder is configured with a large groove. The upper end of the support base is extended into the inner hole of the coupling needle holder, and is formed with first resilient pawls converging toward the center. The outside of the upper end of the support base is configured with a circle flange, which is received in the large groove and is able to slide up and down along the large groove. The lower end of the coupling needle holder is formed with first resilient pawls, and the inner wall of the barrel is correspondingly configured with a small groove to be engaged with the first resilient pawls. The outside of the lower end of the support base is configured with a circle flange shoulder, and the flange shoulder is abutted ith the first resilient pawls. Due to the detachable connection between the needle holder and the barrel, the syringe employing the aforementioned structure may be replaced with needles of different specifications according to the requirement, and the needle holder may be retracted into the batter after injection.本發明關於一種可換針自毀式胰島素注射器,包括針筒、推桿、膠塞、針座,其特徵在於:針筒設有聯接針座,聯接針座由支撐座支撐固定在針筒前端,針頭座向下延伸成型有固定環,聯接針座上端成型有卡環,卡環伸入固定環內孔並與固定環相卡合固定,聯接針座內孔的孔壁上設有大凹槽,支撐座上端伸入聯接針座內孔,支撐座上端成型有向中心聚攏的第一彈性棘爪,支撐座上端外側設有一圈凸台,凸台落在大凹槽內,並可沿大凹槽上下滑動,聯接針座下端成型有第一彈性撐爪,相應地針筒內壁設有第一彈性撐爪可嵌入的小凹槽,支撐座下端外側設有一圈凸台肩,凸台肩與第一彈性撐爪相抵。採用上述結構的注射器,由於針頭座與針筒可拆式連接,可以根據需要更換不同規格的針頭,同時注
