The present invention provides a bilirubin nanoparticle formed by the self-assembly of bilirubin and a composite comprising a hydrophilic polymer, a use thereof, and a preparation method therefor. The bilirubin nanoparticle according to the present invention can release a drug enclosed therein to the outside by being collapsed by light or active oxygen stimulation. The bilirubin nanoparticle according to the present invention exhibits antioxidant, antiangiogenic, anticancer, and anti-inflammatory activities.