A protective device includes a cover body, a tongue piece, a combined structure, a uniform moving structure and a buckle structure.The combined structure makes the back end of the cover body connected with the tail of the tongue piece.The tongue piece has a flexible part to maintain the head of the tongue piece in an open position.The actuation structure is arranged on the tongue piece. When a butterfly needle is retreated into the tongue piece, the actuation structure and the tongue piece come to a closed position from an open position.The buckle structure is arranged on the cover body or tongue piece to prevent the tongue piece from leaving the cover body.In this way, the needle head of the butterfly needle is protected by the cover body and tongue piece, which can maintain the safety of the medical waste recycler, and has the effect of labor-saving and automatic.一種保護裝置，包括一蓋體、一舌片、一結合構造、一致動結構與一卡扣結構。該結合構造讓蓋體後端與舌片尾部聯結在一起。該舌片有一可撓部，使舌片頭部維持在一張開位置。該致動結構設在舌片，在一蝴蝶針具退入舌片時，該致動結構連帶舌片從張開位置來到一閉合位置。該卡扣結構設在蓋體或舌片，阻止舌片離開蓋體。如此，該蝴蝶針具的針頭被蓋體與舌片保護，維護醫療廢棄物回收者的安全，兼具省力與自動等效果。
