Objective To explore the risk factors of functional ischemia in patients with coronary heart disease at high altitude and analyze their diagnostic value. Methods The general clinical data and surgical data of 60 patients with coronary heart disease who underwent coronary angiography in Changdu people's Hospital from January 2022 to August 2023 and underwent Fractional flow reserve（FFR） examination with at least one coronary artery stenosis of 50%-90% were collected. According to the FFR value, they were divided into two groups: FFR＜0.8 and FFR ≥0.8. The clinical data and influencing factors of FFR value between the two groups were compared. Results The hemoglobin(Hb), Low density lipoprotein cholesterol (LDL-C), uric acid(UA), D-dimer and altitude of FFR＜0.8 group were higher than those of FFR≥0.8 group (P＜0.05), while the High-density lipoprotein cholesterol(HDL-C), lymphocyte(Lym) level of FFR≥0.8 group was higher than that of FFR＜0.8 group(P＜0.05). FFR was negatively correlated with hypertension, LDL-C, D-dimer and altitude (P＜0.05). It was positively correlated with Lym and serum HDL-C levels(P＜0.05). Multivariate logistic regression analysis showed that D-Dimer (OR=3.762, 95%CI:1.239-11.417, P＜0.05), Hb (OR=1.076, 95%CI:1.019-1.137, P＜0.05) and LDL-C (OR=3.608, 95%CI:1.365-9.535, P＜0.05) were independent risk factors for FFR, while HDL-C (OR=0.003, 95%CI:0-0.199, P＜0.05) and Lym (OR=0.089, 95%CI:1.365-9.535, P＜0.05) were independent risk factors for FFR. The areas under the curve of Hb and LDL-C were 0.644 and 0.662, respectively. Conclusion For patients with high altitude coronary heart disease, Hb and LDL-C have good predictive ability for functional ischemia, and have certain value in guiding treatment and prevention