The utility model discloses a self-fastening thread end protective sleeve convenient to take down. The device comprises a sleeve head, a limiting rod and a reset spring, a closed valve is arranged onthe inner side of the sleeve head; a retaining ring is arranged on the right side of the closed valve; the retaining ring is positioned on the inner side of the sleeve head; convex strips are arrangedon the inner sides of the retaining rings; the protruding strips are located on the inner wall of the buckling ring, the limiting rods are located on the left side and the right side of the bucklingring and located on the inner side of the sleeve head, extrusion rods are connected to the upper portion and the lower portion of the buckling ring and connected with the sleeve head in a penetratingmode, and an insulating layer is arranged on the inner side of the sleeve head and located on the right side of the buckling ring. According to the self-fastening wire end protective sleeve convenientto take down, the sleeve head is adopted to enable the exposed wire end to be effectively insulated and protected, personnel electric shock caused by mistakenly touching the electrified exposed wireend in work is avoided, the sleeve head is automatically fastened on a cable through the buckling ring, the situation that the sleeve head automatically falls off can be avoided, and the stability ofinsulation protection is improved.