To discuss the application effect of the group health care model for pregnant women with gestational diabetes mellitus (GDM) and subclinical hypothyroidism. Methods: 124 pregnant women with GDM and subclinical hypothyroidism admitted to the hospital were selected as the research subjects between March 2020 and August 2023. These women were divided into observation group and control group (62 cases in each group) by the random number table method. All women in the two groups were given clinical conventional treatments (insulin aspart combined with levothyroxine) and were given the comprehensive nursing management. The women in the observation group were also given the group health care model additionally. The changes of the thyroid function, blood glucose level and psychological states of the women before and after the intervention were compared between the two groups. The pregnancy complications and the adverse pregnancy outcomes of the women in the two groups were recorded. Results: The serum thyrotropin and free thyroxine, the fasting blood sugar, the 2h postprandial blood glucose level and the psychological state of the women in the two groups after treatment had improved significantly, and the improved effect of which of the women in the observation group was significantly better than that of the women in the control group. The scores of the self-rating depression scale (20.54±2.88 points) and the self-rating anxiety scale (22.63±3.01 points) of the women in the observation group were significantly lower than those (31.27±3.14 points and 33.24±3.30 points) of the women in the control group. The incidences of complications (6.5%) and abortion (6.5%) of the women in the observation group were significantly lower than those (19.4% and 0) of the women in the control group (all P<0.05). Conclusion: The group health care model for the pregnant women with GDM and subclinical hypothyroidism can not only stably control their blood glucose level, improve their thyroid function and psychological states, but also can significantly reduce their risk of pregnancy complications and improve their pregnancy outcomes.