A mounting member, for C-shaped slots, comprising a mechanism body , a width of the mechanism body being changeable; wherein the mechanism body is configured to be embedded and restricted within a C-shaped slot from a slot opening of the C-shaped slot , the mechanism body comprises a first assembly and a second assembly , the first assembly is an elastic element, the second assembly is embedded in the first assembly , first assembly is provided with a placing part , and the placing part is provided with a first contact surface on two sides thereof, the second assembly is provided with a second contact surface on two sides thereof, the second assembly is placed in the placing part by contacting the second contact surface with the first contact surface , wherein the second assembly is provided with a threaded hole, and a screw is screwed into the threaded hole; and the screw is rotated to form a spiral push against the second assembly , the screw being moved in a reverse direction relative to the second assembly to enable the second assembly to squeeze against the first assembly , characterized in that the first contact surface is a first inclined surface inclined from top to bottom towards a middle of the first assembly , the second contact surface is a second inclined surface adapted to the first contact surface , the placing part is provided with at least two guiding slots , the second assembly is provided with a guiding block matching the guiding slot , and when the second assembly is mounted on the placing part , the guiding block is inserted to the guiding slot to guide the second assembly . a mechanism body , a width of the mechanism body being changeable; wherein the mechanism body is configured to be embedded and restricted within a C-shaped slot from a slot opening of the C-shaped slot , the mechanism body comprises a first assembly and a second assembly , the first assembly is an elastic element, the second assembly is embedded in the first assembly , first assembly is provided with a placing part , and the placing part is provided with a first contact surface on two sides thereof, the second assembly is provided with a second contact surface on two sides thereof, the second assembly is placed in the placing part by contacting the second contact surface with the first contact surface , wherein the second assembly is provided with a threaded hole, and a screw is screwed into the threaded hole; and the screw is rotated to form a spiral push against the second assembly , the screw being moved in a reverse direction relative to the second assembly to enable the second assembly to squeeze against the first assembly , characterized in that the first contact surface is a first inclined surface inclined from top to bottom towards a middle of the first assembly , the second contact surface is a second inclined surface adapted to the first contact surface , the placing part is provided with at least two guiding slots , the second assembly is provided with a guiding block matching the guiding slot , and when the second assembly is mounted on the placing part , the guiding block is inserted to the guiding slot to guide the second assembly . <EOS>