Subacute thyroiditis， a common inflammatory disease of the thyroid gland， needs drug therapies due to fever， pain and other symptoms. Glucocorticoids and non-steroidal anti-inflammatory drugs （NSAIDs） are mainly used to treat this disease， while they may lead to severe side effects and high recurrence. Traditional Chinese medicine （TCM） demonstrates definite efficacy in alleviating the symptoms and shortening the disease course. The theory of excessive Qi causing fire holds that the excessive Qi of six excesses， seven emotions， or Yang hyperactivity in the Zangfu organs turns into fire and heat， resulting in pathological changes. According to this theory， this paper proposes the research on the pathogenesis and therapies of subacute thyroiditis can be started from the perspectives of Qi and fire. The disordered daily life causes internal injury of body and mind， predominant Yang Qi， or deficiency fire flaming upward， which leads to the invasion of six excesses and pathogenic toxins. Both the internal and external disorders induce the stagnation and the abnormal ascending and descending of Qi. The excessive Qi generates fire， the accumulation of which causes phlegm and stasis in front of the neck， eventually leading to the occurrence of subacute thyroiditis. The clinical and pathogenic characteristics of subacute thyroiditis indicate that the occurrence of this disease is associated with Qi and fire. Therefore， the treatment should focus on purging fire and detoxifying， regulating Qi movement， activating blood， resolving phlegm， and dissipating mass. Shengjiangsan has the effect of clearing heat and toxin， resolving phlegm， dredging collaterals， and dissipating mass， demonstrating definite therapeutic effect on subacute thyroiditis. This paper expounds the mechanism of Shengjiangsan in treating subacute thyroiditis from purging fire and regulating Qi. Furthermore， we preliminarily elaborate on the anti-viral， immunomodulatory， anti-inflammatory， and pain-relieving effects of Shengjiangsan from modern medicine. This paper provides new ideas for the syndrome differentiation and treatment of subacute thyroiditis from the perspectives of Qi and fire and basic ethical support for the clinical and basic research on the treatment of subacute thyroiditis by Shengjiangsan.