Pemphigus vulgaris (PV) is a group of autoimmune bullous diseases characterized by life-threatening intradermal blisters. Hashimoto thyroiditis (HT) is a kind of autoimmune disease with abnormal increase of thyroid peroxidase autoantibody (TPOAb), which is the thyroid specific antibody, leading to hypothyroidism. In recent years, the probability of HT in patients with PV is increasing, and the co-disease may be related to the effect of TPOAb autoantibody on oral keratinocytes. This article reviews the epidemiological relationship between PV and HT and the mechanism of TPOAb in their co-disease, in order to provide ideas for the diagnosis and treatment of both.