Objective To investigate the effects of hepatitis B virus (HBV) and liver function status on the occurrence and development of gestational diabetes mellitus (GDM). Methods The medical data of 628 pregnant women, who underwent prenatal examination and delivery in Chongqing Health Center for Women and Children from January 2018 to October 2021, were collected and retrospectively analyzed. Depending on whether infected with HBV, the patients were divided into HBV positive group(n=389) and HBV negative group (n=239). Those in HBV positive group were then further divided into normal liver function group(n=301) and abnormal liver function group (n=88) according to the liver function status in the second trimester of pregnancy so as to analyze the influence of HBV infection and liver function status on the occurrence and development of GDM. A total of 137 pregnant women who met the diagnostic criteria of GDM were divided into HBV positive group (n=97) and HBV negative group(n=40) according to the different HBV infection status. Those in HBV positive group were then divided into normal liver function group (n=62) and abnormal liver function group (n=35) according to their liver function status in the second trimester, so as to analyze the influence of HBV infection on blood glucose and postpartum blood glucose in GDM patients and adverse pregnancy outcomes. Results The fluctuation of blood glucose levels of pregnancy OGTT 1 h and 2 h was more obvious in pregnant women with positive HBV infection than those in negative group of HBV infection (P<0.05). The incidence of GDM was increased (24.9%vs. 16.7%) and gestational age was shortened in the pregnant women with positive HBV infection (P<0.05). Among the pregnant women with positive HBV infection, the average age, fasting blood glucose in the second trimester, OGTT 1 h, 2 h blood glucose and the incidence of GDM were higher in those with abnormal liver function (39.8% vs. 20.1%) than in those with normal liver function (P<0.05). HBV-infected GDM pregnant women with abnormal liver function developed higher blood glucose level in the second trimester of pregnancy, fasting blood glucose level within 6-12 weeks postpartum and a higher risk of impaired glucose tolerance than those with normal liver function (P<0.05). The incidence of GDM in the second pregnancy of pregnant women with HBV infection was higher than those in the first pregnancy (P<0.05). The rate of cesarean section and postpartum hemorrhage was higher in GDM with HBV infection pregnant women than those GDM pregnant women with normal liver function (P<0.05). Conclusions HBV infection with liver function damage can increase the incidence of GDM. GDM patients with HBV infection and liver function damage have a higher risk of adverse pregnancy outcomes. HBV infection may prolong the recovery time of postpartum blood glucose metabolism in pregnant women.