A mask plate for manufacturing an organic light-emitting diode (OLED) transparent display panel, the OLED transparent display panel and a manufacturing method thereof are disclosed. The mask plate includes a substrate and a plurality of hollowed-out areas and a plurality of opaque areas disposed on the substrate, and a pattern of the hollowed-out areas correspond to a pattern of a cathode of the OLED transparent display panel to be manufactured; and all the hollowed-out areas are communicated with each other.