Objective: To investigate the etiology, clinical features and maternal and infant outcomes of abnormal liver function during pregnancy. Methods: A total of 100 patients with abnormal liver function during pregnancy accepted by Tongzhou Maternal & Child Health Hospital of Beijing from January 2018 to January 2021 were selected as the observation group, 100 cases of pregnant women with normal liver function who underwent a check-up in our hospital during the same period were selected as the control group, and the liver function indexes and pregnancy outcome of the two groups were compared. Results: In the observation group, the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL), and total bile acid (TBA) were higher than the control group, and the albumin (ALB) level was lower than the control group (P<0.05). Among the 100 patients in the observation group, 71.00% were in the early and second trimester and 29.00% were in the third trimester. The levels of ALT, AST, TBIL and TBA in the third trimester of pregnancy were significantly higher than those in the first and second trimesters of pregnancy, and the levels of ALB were low in the first and second trimesters of pregnancy (P<0.05).The main cause of abnormal liver function in the observation group was drug-induced hepatitis (46.00%), and the levels of ALT, AST, TBIL, and TBA in patients with different causes were obviously abnormal. In the observation group, the incidence of adverse pregnancy outcomes was 13.00%, which was higher than 4.00% in the control group (P<0.05). Conclusion: The related liver function indexes of patients with abnormal liver function during pregnancy are obviously abnormal, and they are mostly concentrated in the first and second trimester. The degree of abnormal liver function in the third trimester is higher than that in the early and mid-gestation period. The main cause is drug-induced hepatitis. The abnormal liver function can increase risk of adverse pregnancy outcome during pregnancy.