A supporting back film includes a first supporting structure and a second supporting structure arranged on at least one side of the first supporting structure in a second direction. The second direction intersects with the first direction. An orthographic projection of the first supporting structure on the flexible display panel covers the bendable region, and the first supporting structure is bendable. The volume of the second supporting structure is greater than or equal to the volume of the first supporting structure, and the density of the second supporting structure is less than the density of the first supporting structure. Alternatively, the volume of the first supporting structure is greater than or equal to the volume of the second supporting structure, and the density of the first supporting structure is less than the density of the second supporting structure.