This cross-sectional study aimed to explore the associated factors of depression in primiparas with hypothyroidism during pregnancy. The research subjects were 200 primiparas with hypothyroidism during pregnancy who were admitted to our hospital between December 2016 and December 2019. Self-rating depression scale scores were used to evaluate the depression, and the incidence of depression were examined. The data from all the subjects were collected to compare the differences between primiparas with hypothyroidism during pregnancy with and without depression. A logistic regression equation was used to analyze the influencing factors of depression in these patients. Of the 200 primiparas who took part in this study, 27 suffered from depression, accounting for 13.50%. There were differences in age, education level, economic income, sleep quality, and conjugal relations between the depressed and the nondepressed participants. When the above factors were included in the logistic regression equation, it was found that the odds ratio values for these factors were all >1, which indicated that they had an influence on maternal depression in primiparas with hypothyroidism during pregnancy. This study demonstrated that pregnancy-associated hypothyroidism in primiparas is affected by age, education level, economic income, sleep quality, and conjugal relations, all of which increase the incidence of depression. Relevant preventive measures should be provided in clinical practice to avoid the occurrence of depression.