Bilirubin was extracted from pig bile by hydrolysis.The effects of antioxidant dosage, alk. hydrolysis pH, hydrolysis temperature and time, acidification pH on the extraction rate and content of bilirubin were studied.The results showed that the optimal extraction conditions of bilirubin by hydrolyzing method were as follows: dosage of antioxidant was 0.5%, pH of alk. hydrolysis was 11.0∼11.5, hydrolysis temperature was 75∼80°C, time was 10 min, pH of acidification was 5.5∼6.0, the extraction rate of bilirubin was 95%, the content was more than 98.0%.