Telescopic needle cap for injector

The utility model discloses a telescopic needle cap for an injector. The telescopic cap comprises a telescopic cap body arranged on a syringe needle in a sleeving mode. One end, close to the needle tip, of the telescopic cap body is open; a detachable buckling cap is arranged at the end, located at the needle tip, of the telescopic cap body, the telescopic cap body is formed by sequentially sleeving a plurality of hollow telescopic joints, the diameters of the telescopic joints are gradually decreased from the end close to the needle tip to the end of the needle plug, and the needle stem is exposed by compressing the telescopic joints from the end close to the needle tip to the end of the needle plug. The syringe has the advantages of being capable of effectively avoiding the situation that people are punctured carelessly when the syringe is used, and meanwhile guaranteeing sterility, safety and sanitation of the needle stem. 一种注射器用伸缩针帽，包括套设在注射器针头上的伸缩帽身，伸缩帽身靠近针尖的一端端部开口，另一端与针栓螺纹连接，伸缩帽身位于针尖的一端设有可拆卸的扣压帽，所述伸缩帽身由多