Inclusion Criteria:  Clinical diagnosis of type 2 diabetes. Aged 18-70; HbA1c ≥ 8.0%  Exclusion Criteria:  Pregnancy; Chronic kidney disease (CKD stage 5); Senile dementia patients; With malignant tumor; Moderate and severe anemia; Severe liver dysfunction; Hemolytic anemia, aplastic anemia, massive blood loss or transfusion, chronic malaria; In the recent one week, large doses of salicylate, erythropoietin, antiretroviral drugs, ribavirin and other drugs that have an impact on the detection of glycosylated hemoglobin were used