Objective To discuss the risk factors and pregnancy outcomes of gestational diabetes mellitus(GDM) for GDM prevention and treatment in Nanchong area. Methods This study enrolled 1,800 pregnant women who performed prenatal check-up and delivery in Affiliated Hospital of North Sichuan Medical College from July 1, 2018 to September 30, 2019. Among the subjects, 537 cases were diagnosed GDM (GDM group), 1,263 cases with normal blood glucose (NGT group).The key observation involved the incidence, risk factors and pregnancy outcomes of GDM. Results In Nanchong area, the incidence of GDM was 29.83%. Age, residence, prenatal body mass index(BMI), polycystic ovary syndrome(PCOS), hepatitis B surface antigen(HBsAg), hypertensive disorder of pregnancy(HDP), thyroid function during pregnancy, scar uterus, in vitro fertilization(IVF), abortion history and delivery history were related to the onset of GDM. GDM was related to cesarean section, HDP, intrahepatic cholestasis of pregnancy(ICP), postpartum hemorrhage, preterm delivery, and macrosomia(all P<0.05). The risk factors of GDM were age, residence, prenatal BMI, PCOS, HBsAg, HDP, thyroid function during pregnancy, IVF and abortion history. GDM was a risk factor for cesarean section, HDP, ICP, postpartum hemorrhage and macrosomia (all P<0.05). Conclusion In Nanchong area, the incidence of GDM may be closely related to age, residence site, prenatal BMI, PCOS, HBsAg, HDP, thyroid function during pregnancy, IVF and abortion history. The risks of cesarean section, HDP, ICP, postpartum hemorrhage and macrosomia were higher in pregnant women with GDM.