Erythropoietic protoporphyria (EPP) is an inherited metabolic disease caused by the deficiency in ferrochelatase (FECH) encoded by the gene, and it is inherited in an autosomal recessive manner. EPP usually produces acute pain photosensitivity after exposure to sunlight in infancy or early childhood, and liver failure is the most serious associated complication. This article reported an adult female case of EPP complicated with thyrotoxicosis and liver dysfunction which is a rare condition. The patient's liver function improved after liver protection treatment, her thyroid function returned to normal, and her EPP symptoms improved significantly. Moreover, the c.286C>T gene mutation may be the pathogenic locus of EPP. For patients with abnormal liver function, the possibility of EPP should be considered after the common causes are excluded, and gene detection should be done to confirm the diagnosis in time. When EPP is associated with thyrotoxicosis and liver dysfunction, priority may be given to hepatoprotective therapy.