Abstract: Objective To observe the clinical effect of Yunyu Decotion combined with western medicine in treating type 2 diabetes mellitus with Yin deficiency and heat excess syndrome, so as to explore the effective treatment of the disease and promote the improvement of patients' quality of life. Methods A total of 96 patients with type 2 diabetes admitted to our hospital from February 2018 to February 2019 were randomly divided into control group (n=48) and observation group (n=48). The two groups were treated with metformin and Yunyu Decotion combined with metformin on the basis of routine treatment respectively. The changes of syndrome integral, clinical efficacy, blood sugar level (fasting blood sugar, 2 h postprandial blood sugar and glycosylated blood sugar) and adverse reactions (diarrhea, dizziness, headache and rash) were compared between the two groups. Results After treatment, the syndrome score of the observation group (5.72±1.81) was lower than that of the control group (8.62±2.65), the total effective rate of the observation group (93.75%) was higher than that of the control group (79.17%). After treatment, the fasting blood glucose, postprandial blood glucose, glycosylated hemoglobin (7.31 mmol/L±1.24 mmol/L, 8.72 mmol/L±2.19 mmol/L, 3.82%±1.44%) of the observation group were lower than that of the control group (8.64 mmol/L±3.37 mmol/L, 13.07 mmol/L±2.35 mmol/L, 5.05%±2.18%). The incidence of adverse reactions in the observation group (4.17%) was similar to that in the control group (6.25%). There was no significant difference between the two groups (all P>0.05). Conclusion Yunyu Decotion combined with western medicine has a significant clinical effect in treating type 2 diabetes mellitus with Yin deficiency and heat excess syndrome. It can significantly reduce the syndrome score, improve the blood sugar level of patients, and have fewer adverse reactions. It is worth promoting.