Objective To explore the application effects of serious games in dietary health education for patients with gestational diabetes mellitus (GDM), and to provide evidence for related health education practices. Methods A total of 64 patients with GDM were randomly assigned to a control group and an intervention group, with 32 cases in each group. The control group received conventional dietary health education, while the intervention group received serious game-based dietary health education in addition to conventional education.Fasting blood glucose, 2-hour postprandial blood glucose, dietary knowledge scores and the compliance rate of dietary structure of patients in the two groups were compared before and after the intervention. Results Thirty participants in each group completed the study. After the intervention, the intervention group had lower levels of fasting blood glucose and 2-hour postprandial blood glucose, as well as higher dietary knowledge scores and dietary structure compliance rates than the control group (all P<0.05). Conclusion Serious game-based dietary health education exerts positive effects on improving patients′ dietary knowledge and optimizing dietary structure, and helps lower blood glucose levels of patients with GDM. Serious games can serve as an effective supplementary intervention method for dietary health education among women with GDM.