Disclosed are a packaging cover plate, an organic light-emitting diode display and a manufacturing method therefor. The packaging cover plate comprises: a cover plate body, the cover plate body being provided with open slots; cover plugs for covering openings at two ends of the open slots; and water absorption layers for at least covering mouths of the open slots. By means of the arranged open slots, the packaging cover plate can conveniently introduce a dry gas. In addition, the water absorption layers absorb water vapour, the introduced dry gas dries the water absorption layers, and the water vapour and oxygen in the water absorption layers can be taken away by means of the circular flow of the dry gas, so that damage to a device by water vapour and oxygen can be reduced, and the packaging effect is better.