An apparatus is disclosed for aligning a to-be-aligned display panel by self-alignment exposure, a first and second groups of pixels are distributed at intervals on the to-be-aligned display panel which includes a first and second substrates, a first polarizer is provided on the first substrate, and a light alignment layer is provided on the first polarizer, wherein the apparatus includes a base platform for placing the to-be-aligned display panel; a display panel driving system connected to the to-be-aligned display panel; light irradiating toward the first substrate from the second substrate is linearly polarized light; a first exposure light source located to be closer to the second substrate; a second exposure light source located to be closer to the first substrate, light emitted from the second exposure light source is linearly polarized light, the polarization direction of which is orthogonal to the transmission axis direction of the first polarizer.