The disclosure relates to a high-aperture-ratio microdisplay with a microcavity structure. The microdisplay comprises a substrate, unit pixels, driving elements, and organic light-emitting diodes. The organic light-emitting diodes each comprise: an anode, an organic emission layer, and a cathode. The anode is formed by sequentially stacking a reflecting electrode, a first dielectric layer, a second dielectric layer, and a transparent electrode. The organic emission layer is stacked over the anode. The cathode is stacked over the organic emission layer. The first dielectric layer and the second dielectric layer have contact portion that open at least one corner of the reflecting electrode. The anode is connected to the reflecting electrode through the contact portions.