Objective To explore the intervention effect of diet nursing combined with health education on blood glucose control and pregnancy outcome of gestational diabetes mellitus.Methods: A total of 84 patients with gestational diabetes mellitus admitted to our hospital from February 21 to June 20 were selected as the research objects, and randomly divided into control group (routine nursing) and observation group (routine nursing + dietary nursing + health education) with 42 cases each.Blood glucose level, health knowledge, adverse pregnancy outcomes and intervention satisfaction were compared between the two groups.Results: After intervention, the blood glucose (fasting blood glucose / 2h postprandial blood glucose/HBA1c) level in the observation group was lower than that in the control group (P<0.05).Compared with the control group, the score of health knowledge (drug use/blood glucose monitoring/exercise, childbirth, exercise related) was higher in the observation group (P<0.05).The incidence of adverse pregnancy outcome (observation group =7.14%/ control group =23.81%) was lower in the two groups (P<0.05).The intervention satisfaction of the two groups (observation group =95.24%/ control group =78.57%) was higher in the observation group (P<0.05).Conclusion: During the treatment of gestational diabetes mellitus, the intervention effect of diet nursing and health education is ideal, which can promote the improvement of patients'' blood glucose level and pregnancy outcome, deepen patients'' health knowledge and improve patients'' satisfaction with intervention, and the feasibility of promotion is relatively high.