A winding member assembly includes a first winding member and a second winding member. The first winding member includes two first sub-winding members movable relative to each other along a first direction. The first winding member is provided with second winding members on two sides along a second direction respectively. In a first state, an outer peripheral wall of the second winding member and an outer peripheral wall of the first sub-winding member are in a same preset cylindrical surface. In a second state, the second winding member is located inside the preset cylindrical surface and at least part of the second winding member extends into an accommodating cavity through a corresponding fitting opening, so that a width of the winding member assembly in the second state in the second direction is smaller than a width of the winding member assembly in the first state in the second direction.