To observe the effect of modified Yuye Decoction on type 2 diabetes mellitus and its effect on β cell function and carotid intima-media thickness.Methods：A total of 90 patients with type 2 diabetes in the internal medicine of Dezhou Hospital of Traditional Chinese Medicine were selected during the period of January 2017 to December 2017.The patients were selected as the treatment group and the control group respectively according to the sequence of medical treatment，with 45 cases in each group.The control group received oral administration of Metformin Hydrochloride Sustained Release Tablets on the basis of treatment.The treatment group was given Yuye Decoction on the basis of the control group for 3 months.Before and after treatment，two groups of patients with early morning blood 10 mL were collected，and the automatic biochemical analyzer was used to test the patients' fasting blood glucose and postprandial 2 h blood sugar，serum cholesterol(TC)，glycerin three fat(TG)，high density lipoprotein cholesterol(HDL-C)and low density lipoprotein cholesterol(LDL-C).At the same time，fasting insulin(FINS)and C peptide(C-Peptide，C-P)were measured.According to the formula，the function of HOMA-β cell function insulin secretion index(HOMA-Beta Cell function Index，HBCI)and insulin resistance index were calculated，and the specific human neck of the ultrasound department was carried out.Carotid artery INTIMA-MEDIATHICKNESS was measured by color Doppler ultrasound(IMT).Results：After treatment，fasting blood glucose and postprandial 2 h blood glucose were significantly decreased in the 2 groups(P<0.05)，and the treatment group was better than the control group(P<0.05).After treatment，the levels of TG，TCHO，HDL-C and LDL-C were significantly lower than those before treatment(P<0.05)，but there was no significant difference between the treatment group and the control group after treatment(P>0.05).After treatment，the levels of FINS，C-P and HBCI in the 2 groups increased significantly，and the IRI decreased significantly(P<0.05)，but after treatment，there was no significant difference between the treatment group and the control group(P>0.05).After treatment，the carotid artery intima-media thickness of the two groups was significantly lower than before treatment(P<0.05)，and the treatment group was better than the control group(P<0.05).Conclusion：Modified Yuye Decoction in the treatment of type 2 diabetes patients can improve the function of beta cell，improve the thickness of the medial membrane of the carotid artery，and postpone the progress of the major vascular diseases.It has a vital role in the development of human health and social and economic development.