Abstract: Bilirubin is a metabolite of senescent red blood cells in the human body. Although it possesses certain toxicity at higher concentrations, recent studies have shown that bilirubin has potential pharmacological effects, including anti-oxidant, anti-inflammatory and neuroprotective effects. In addition, bilirubin is also the main raw material for the artificial cow-bezoar, and its content serves as a crucial criterion for assessing the quality of artificial bezoar. Currently, the main source of bilirubin is extracted from animal bile, however, the low content of bilirubin in bile and the limited resources of animal bile sources lead to its high production cost. Bilirubin is a complex molecule, and its low solubility in water makes its chemical synthesis difficult and its purity low. In recent years, immobilised enzyme technology and the construction of microbial cell factories have made remarkable progress in the biosynthesis of bilirubin and its precursor substances, providing a new pathway for the production of bilirubin and its application as a pharmaceutical preparation. This review summarizes the physiological functions, acquisition, and current synthesis status of bilirubin based on a review of domestic and international literature from the past five years, retrieved from the Web of Science, CNKI, and PubMed databases, with the aim of providing a reference for the further application of bilirubin in the future.