Objective To analyze the application effect of stage nursing intervention in patients with gestational diabetes mellitus and its effect on postpartum incision healing. Methods A total of 100 patients with gestational diabetes mellitus who gave birth in our hospital from January 2021 to January 2022 were selected as the research objects. They were divided into control group and observation group by random number table method, with 50 patients in each group. The control group was given routine nursing, and the observation group was given stage nursing intervention on the basis of the control group. The blood glucose, natural delivery rate and postpartum incision scar score were compared between the two groups. Results The levels of fasting blood glucose and 2 h postprandial blood glucose in the observation group were lower than those in the control group (P