Mood disorders are based on mood or emotional changes， often characterized by low or high mood， and most symptoms secondary to mood changes. Such disease attack is usually related to stress events and other factors， easy to relapse， and the economic burden of the disease is heavy. The treatment of mood disorders is mainly drug treatment. After receiving monotherapy， parts of patients' symptoms can be completely relieved， while the efficacy of monotherapy alone is not enough for some patients. Therefore， there is an urgent need for new treatment methods as an adjunctive for mood disorders. As a non-invasive brain stimulation technique， transcranial direct current stimulation（ tDCS） has been widely used in mood disorders for more than ten years， which has the characteristics of easy operation， low cost and high safety. It has been proved that tDCS alone or combined with drug therapy can effectively treat some patients with mood disorders， but there is no recommended best treatment parameters and the specific mechanism remains unclear. The mechanism， parameters， efficacy， limitation and prospect of tDCS in the treatment of mood disorders（ mainly depression and bipolar disorder） will be reviewed in order to provide the basis for the future research and clinical application of transcranial direct current stimulation.