A phototherapy patch is disclosed, which includes: an adhesive layer, having a first surface and an opposite second surface; a pharmaceutical drug layer, disposed on the first surface of the adhesive layer; and a spontaneous emission layer, disposed over the pharmaceutical drug layer and capable of emitting therapeutic light by light illumination or a chemical reaction. Accordingly, the phototherapy patch according to the present invention has no power supply disposed therein, and thereby is suitable to be manufactured as a particularly thin and thus inconspicuous device.