To investigate the application effect of the nursing intervention based on cross-theoretical model for the self-management awareness and the blood glucose control of pregnant women with gestational diabetes mellitus (GDM). Methods: 120 pregnant women with GDM were selected in 01-120 sequential numbering and were divided into two groups (60 cases in each group) based on the dual or singular numbering during the period of July 2021-June 2023. The women in the two groups were given the conventional nursing for 4 weeks, while the women in the research group were given the trans-theoretical modeling nursing additionally. The self management consciousness, the glycemic control status and the complications indicators changes of the pregnant women were compared between the two groups. Results: The consciousness of self management behavior score of the women in the two groups after 4 weeks of intervention had increased significantly, and which of the women in the research group was significantly higher than that of the women in the control group. The changes of the blood glucose levels of the women in the two groups after intervention had decreased significantly. The level of the postprandial 2h blood glucose  (6.55±1.50mmol/L) and the glycosylated hemoglobin (5.52±1.35%) of the women in the research group were significantly lower than those (7.36±1.38 mmol/L and 6.35±1.37%) of the women in the control group. The total incidence (1.7%) of complications, such as the hypertensive disorders of pregnancy, the premature rupture of membranes and the hypoglycemia and eclampsia, of the women in the research group was significantly lower than that (13.3%) of the women in the control group (all P<0.05). Conclusion: The trans-theoretical model nursing for the pregnant women with GDM can effectively enhances their self-management awareness and behavior, maintain their stable blood glucose level during pregnancy, and reduce their occurrence of complications.