Hematochromatosis is caused by the excessive iron load in various organs and systems, which leads to dysfunction and a series of complications. According to the etiology, hematochromatosis can be grouped into primary and secondary forms. In this paper, we reported a case of beta thalassemia secondary hematochromatosis which was first diagnosed as diabetic ketoacidosis. The patient, male, 31-year-old, showed polyuria and polydipsia for 2 years, aggravation for more than 10 days, fatigue and poor appetite with nausea and vomiting for 2 days. Physical examination indicated skin pigmentation and liver enlargement. Laboratory tests suggested diabetic ketoacidosis, anemia and increased serum ferritin (SF). Finally, thalassemia gene test confirmed intermediate β-thalassemia. Therefore, when screening for associated causes in newly diagnosed diabetes, patients with high levels of ferritin, should be particularly alert for the occurrence of hematochromatosis.