Objective: To study the effect of telmisartan combined with lipid-lowering drug therapy on serum lipid metabolism index and cytokine levels in patients with type 2 diabetes mellitus complicated by coronary heart disease. Methods: A total of 106 patients with type 2 diabetes mellitus complicated by coronary heart disease who were treated in our hospital between September 2013 and October 2016 were collected and then divided into the control group (n=55) who received conventional treatment + lipid-lowering drug treatment and the observation group (n=51) who received conventional treatment + lipid-lowering drug + telmisartan treatment after the therapies were reviewed. Before and after treatment, serum levels of lipid metabolism indexes, inflammatory mediators and oxidative stress indexes were compared between two groups of patients. Results: Before treatment, the differences in serum levels of lipid metabolism indexes, inflammatory mediators and oxidative stress indexes were not statistically significant between two groups of patients. After treatment, serum TG and LDL-C levels in observation group were lower than those in control group while HDL-C level was higher than that in control group; serum inflammatory mediators IL-6, IL-8, HMGB1 and TNF-α levels were lower than those in control group; serum oxidative stress indexes MDA and ROS levels were lower than those in control group while GSH-Px level was higher than that in control group. Conclusion: Telmisartan combined with lipid-lowering drug therapy can effectively optimize the lipid metabolism and reduce the systemic inflammatory response and oxidative stress response in patients with type 2 diabetes mellitus complicated by coronary heart disease.