Objective To explore the core symptoms of night eating behavior in pregnant women and its relationship with prenatal depression, in order to provide a basis for the prevention and intervention of night eating behavior in this population. Methods A total of 797 pregnant women undergoing prenatal check-ups were selected as research subjects, and data was collected by the Edinburgh Postnatal Depression Scale and Night Eating Questionnaire. Results The scores of prenatal depression scores was(6.09±4.45) and night eating behavior scores was(11.83±5.46).Regression analysis showed that prenatal depressive moods can significantly positively predict night eating behavior (P<0.05). Network analysis indicates that "Waking up in the middle of the night with a craving for food" (rs=1.29) was the most intense symptom in night eating behavior, while "I am so unhappy that I have insomnia" (rbs=1.80) was the most important bridging node connecting prenatal depression to night eating behavior. The results of the network comparison showed that there was no significant difference in the overall network structure between pregnant women <30 and ≥30 years of age. However, in pregnant women aged ≥30, the local edge connections in the night eating symptom network were stronger(r=0.17, vs.0.04, P<0.05); whereas in pregnant women ＜30 years old, the local edge connections in the network relating prenatal depression to night eating behavior were more tightly connected(r=0.10, vs.0.02, P<0.05). Conclusion The level of night eating behavior in pregnant women is generally higher than that in the general population, with the core symptom manifesting as the craving for food at night. Prenatal depression in pregnant women can significantly positively predict night eating behavior, and "unhappiness leading to insomnia" is a bridging node affecting night eating, with a certain difference in the association between the two in different age groups. Therefore, night eating behavior in pregnant women deserves attention. Preventing and controlling prenatal depression, especially insomnia caused by low mood, may be a potential intervention target for the prevention and intervention of night eating behavior during pregnancy.