To explore the effect of the metformin combined with diversified nursing intervention for treating pregnant women with gestational diabetes mellitus(GDM), and to study its influence on the quality of life, self-management ability and pregnancy outcomes of the women. Methods: A total of 88 full-term pregnant women with GDM were selected and were randomly divided into two groups(44 cases in each group) by digital table method from January 2019 to December 2022. The women in the control group were given diversified nursing intervention till delivery, and the women in the study group were given diversified nursing intervention combined with metformin treatment till delivery. The changes of the blood glucose and insulin levels, the vascular endothelial function, the quality of life, and the self-management ability and other indicators of the women before and after treatment, and the incidence of adverse pregnancy outcomes of the women in the two groups were monitored. Results: The levels of the glycosylated hemoglobin, the 2-hour postprandial blood glucose, the fasting blood glucose, the fasting insulin concentration and the insulin resistance index value of the women in the study group after treatment were significantly lower than those of the women in the control group. The vasodilation function of the women in the study group after treatment was significantly higher than that of the women in the control group. The levels of vascular endothelial growth factor and vascular cell adhesion factor-1 of the women in the study group after treatment were significantly lower than those of the women in the control group. The proportion of the hypertension(13.6%) of the women in the study group was significantly lower than that(31.8%) of the women in the control group. The scores of the quality of life specificity scale(84.63±10.24 points) and the Michigan diabetes management rating scale(15.63±3.14 points) of the women in the study group were significantly higher than those(59.77±8.94 points and 13.56±2.98 points) of the women in the control group. The number of the neonatal hypoglycemia(3 cases) and the incidence adverse pregnancy outcomes(13.6%) of the women in the study group were significantly lower than those(7 cases and 34.1%) of the women in the control group(all P<0.05). Conclusion: Metformin combined with the diversified nursing intervention for treating the pregnant women with GDM can effectively promote their quality of life and self-management ability, improve their normalization of blood glucose and insulin levels and increase their vascular endothelial function, and which can decrease the adverse pregnancy outcomes of the women.