To investigate the relationship among the serum lipid metabolism indexes, high sensitivity C-reactive protein (hs-CRP), mean platelet volume (MPV) level, carotid intima-media thickness (IMT), Genisini score and thyroid gland functional indicators in patients with coronary heart disease and subclinical hypothyroidism, to provide reference for treatment of disease in clinical late stage.Methods The clinical data of 80 patients with coronary heart disease admitted to Chengdu Western Hospital from December 2016 to April 2021 were retrospectively analyzed, the patients were divided into the normal group (50 cases, without subclinical hypothyroidism) and the hypothyroidism group (30 cases, with subclinical hypothyroidism) according to their thyroid function. The cardiac function, biochemical indexes, severity of coronary artery lesions, and thyroid gland functional indicators of patients between the two groups were compared, and the correlation between the clinical indexes and thyroid gland functional indicators was analyzed by Pearson correlation analysis method. Results The levels of serum total cholesterol (TC), triacylglycerol (TG), low-density lipoprotein cholesterol (LDL-C), hs-CRP, thyroid-stimulating hormone (TSH), the level of plasma MPV and Genisini score of patients in the hypothyroidism group were significantly higher than the normal group, while the level of serum high-density lipoprotein cholesterol (HDL-C) was significantly lower than the normal group, the IMT was significantly higher than the normal group (all P<0.05); After comparison of the left ventricular end-diastolic diameter (LVEDD), left ventricular ejection fraction (LVEF) levels, lesion location, serum free triiodothyronine (FT3), free thyroxine (FT4) levels and myocardial infarction ratio of patients between the two groups, the results showed that, the difference was no statistical significance (all P>0.05). The results of Pearson correlation analysis showed that, serum TC, TG, LDL-C, hs-CRP and plasma MPV levels, IMT, Genisini score were positively correlated with serum TSH levels (r =0.398, 0.454, 0.416, 0.425, 0.529, 0.637, 0.214), serum HDL-C level was negatively correlated with serum TSH level (r =-0.521) (all P<0.05). Conclusion Subclinical hypothyroidism can aggravate the condition of patients with coronary heart disease, through blood lipid metabolism, inflammatory response and other ways, and serum TC, TG, LDL-C, hs-CRP, plasma MPV, IMT and Genisini levels are positively correlated with serum TSH levels, while serum HDL-C level is negatively correlated with serum TSH level, Clinically, the risk factors that may cause subclinical hypothyroidism can be found in time and formulate effective prevention measures, through detecting the above biochemical indicators in patients.