Hyperthyroidism is a complication of the treatment of hyperthyroidism, which is manifested by the protrusion of the eyes, or what we call the eyes protruding forward. 1, hyperthyroidism complications caused by untimely treatment of hyperthyroidism, after the cure of hyperthyroidism, generally speaking, the symptoms will then be reduced. 2, genetic factors: human cytocompatibility antigen (HLA) and proptosis have a close relationship, with proptosis in patients with hyperthyroidism, HLABgDR3 locus positive than in patients without hyperthyroidism. 3, autoimmune in vitro cell culture animal model of humoral immunity: it is generally believed that proptosis is an autoimmune disease. 4. Role of retrobulbar fibroblasts: Immunohistochemical staining showed the presence of IGF-I in extraocular muscles, adipocytes, and inflammatory infiltrating cells, while IGF-I and fibroblast generating factor (FGF) have a stimulating effect on fibroblasts. Therefore, the development of proptosis is related to this. 5, environmental factors: Trail observed hyperthyroidism patients, found that 83% of those with proptosis smoked, while only 40% of those without proptosis smoked, suggesting that smoking may be involved in the development of proptosis. It seems that hyperthyroidism, genetic factors, cellular immunity, humoral immunity, the role of post-bulbar fibroblasts and environmental factors together are the causes of proptosis, and can be effectively prevented by catching hyperthyroidism.