Objective：To observe the clinical effect of Zhibai Dihuang tang combined with metformin hydrochloride tablets for type 2 diabetes of fire hyperactivity due to yin deficiency type.Methods：Divided 166 cases of patients with type 2 diabetes of fire hyperactivity due to yin deficiency type into the control group and the treatment group randomly，83 cases in each group.Both groups were given metformin hydrochloride tablets and basic treatment，while the treatment group additionally receivedZhibai Dihuang tang.After two months of treatment，scored each Chinese medicine symptom in the patients，detected glycosylated hemoglobin content and evaluated the curative effect.Results：The total effective rate was 93.98% in the treatment group and was 74.70% in the control group，the difference being significant(P＜0.05).After treatment，glycosylated hemoglobin levels in both groups were lower than those before treatment；glycosylated hemoglobin levels in the treatment group were lower than those in the control group(P＜0.05)；the difference of glycosylated hemoglobin levels before and after treatment in the treatment group was higher than that in the control group(P＜0.05).After treatment，scores of dry mouth and throat，vexation and insomnia，thirst，soreness-tired of waist and knee，hot flush and night sweat，constipation and the total Chinese medicine symptom scores in both groups were lower than those before treatment(P＜0.05).Six terms of Chinese medicine symptom scores and the total Chinese medicine symptom scores in the treatment group were lower than those in the control group(P＜0.05).Comparing with the control group，the difference of total Chinese medicine symptom scores before and after treatment in the treatment group was higher(P＜0.05).Conclusion：Zhibai Dihuang tang combined with metformin hydrochloride tablets for type 2 diabetes offire hyperactivity due to yin deficiency type can effectively improve symptoms of patients and enhance the clinical effect.