For example, as illustrated in FIG. 4, the cover plate 30 includes a window portion 32 located in the display region and a light shielding portion 31 located outside the display region (i.e., the light shielding portion 31 is located in the frame region), and the orthographic projections of the plurality of cover plate alignment marks 14 on the base substrate 11 are located in a region where an orthographic projection of the light shielding portion 31 on the base substrate 11 is located. In this case, connecting the display substrate 10 formed with the plurality of cover plate alignment marks 14 to the cover plate 30 by using the optical adhesive layer 20 includes: irradiating the cover plate and the display substrate by light, and aligning the display substrate 10 with the cover plate 30 by using the plurality of cover plate alignment marks 14 and the light shielding portion 31, as illustrated in FIG. 6. For example, in the process of irradiating the cover plate 30 and the display substrate 10 by light, an alignment device 80 can calculate a center of the display region of the display substrate 10 according to the plurality of cover plate alignment marks 14 included in the display substrate 10, and the alignment device 80 can calculate a center of the window portion 32 of the cover plate 30 according to an inner edge 31A of the light shielding portion 31 in the cover plate 30 (that is, the edge of the display region). The alignment device 80 can align the display substrate 10 with the cover plate 30 by aligning the center of the display region of the display substrate 10 with the center of the window portion 32 of the cover plate 30. In addition, during the alignment process, the display substrate 10 and the cover plate 30 are connected together through the optical adhesive layer 20.
