Aim To explore the correlation between atherogenic index of plasma (AIP), triglyceride-glucose (TyG) index and their severity in patients with chronic coronary syndrome (CCS). Methods A total of 298 patients diagnosed with CCS by coronary angiography were retrospectively selected from Cardiology Department of the First Hospital of Lanzhou University, from May 2017 to May 2023. Clinical indexes were collected and Gensini scores were calculated based on the results of the coronary angiography, clinical data of different Gensini integral groups was compared. Linear regression was used to analyze factors that influence the elevation of Gensini scores, and receiver operator characteristic (ROC) curve was used to determine the predictive value of AIP and TyG index for the severity of coronary artery lesions in CCS. Results The research sample consisted mostly of males (77.9%) with a mean age of (61.9±8.0) years. The adjusted AIP (aAIP) and TyG index of high Gensini score group were higher than those of low Gensini score group and medium Gensini score group, and the differences were significant. Linear regression analysis revealed that total cholesterol (TC), high density lipoprotein cholesterol (HDLC), aAIP and TyG index were the factors influencing the elevated Gensini scores (all P＜0.05). Correlation analysis revealed that aAIP and TyG index were negatively correlated with left ventricular ejection fraction (LVEF), positively correlated with Gensini scores, and positively correlated with stent implantation and the number of stent implantation (all P＜0.05). The ROC curve results indicated that when the aAIP threshold was 1.924, the area under the ROC curve (AUC) for predicting Gensini score ≥41 points was 0.583 (95%CI 0.525～0.640), with a sensitivity of 92.62%, a specificity of 25.50%, and Yoden index of 0.181. When the TyG index threshold was 8.748, the AUC for predicting Gensini score ≥41 points was 0.768 (95%CI 0.716～0.815), with a sensitivity of 77.18%, specificity of 67.11%, and Yoden index of 0.443. Conclusion The aAIP and TyG index were positively correlated with the severity of coronary artery disease in CCS patients. Both elevated levels can predict the severity of coronary lesions in CCS patients, but TyG index showed superior predictive ability compared with aAIP.