The present disclosure provides an organic light-emitting device including a substrate, a pixel defining layer disposed on the substrate, a plurality of supporting members disposed on the pixel defining layer, and at least one organic light-emitting diode disposed on the substrate. The pixel defining layer defines a plurality of pixel regions. The plurality of pixel regions includes a plurality of first pixel regions, a plurality of second pixel regions, and a plurality of third pixel regions. The supporting members are located at first junction regions between the first pixel regions, the second pixel regions, and third pixel regions. 25 to 350 supporting members are provided on every square millimeter of the substrate. The organic light-emitting diode includes an anode, an organic light-emitting layer, and a cathode. The present disclosure further provides a method for manufacturing the organic light-emitting device and a mask for making the supporting member.