Aim To investigate the correlation between blood lipid level and the severity of coronary artery calcification (CAC) in peritoneal dialysis (PD) patients with chronic kidney disease (CKD). Methods 205 CKD patients treated with PD in our hospital from June 2018 to December 2021 were selected as the study subjects, according to the CAC scores, they were divided into calcified group (n＝152) and non-calcified group (n＝53), and the patients in calcified group were divided into mild calcification group (n＝61), moderate calcification group (n＝50), and severe calcification group (n＝41). The differences in clinical data and laboratory indicators were compared through univariate analysis. The restricted cubic spline fitting Logistic regression model was used to analyze the relationship between blood lipid levels and CAC. Multiple Logistic regression model was used to analyze the influencing factors, receiver operating characteristic (ROC) curve was drawn to explore the predictive value of blood lipid levels for the severity of CAC. Results Compared with the non-calcified group, the age, diabetes ratio, body mass index(BMI), triglyceride(TG), total cholesterol(TC), low density lipoprotein cholesterol(LDLC), and blood phosphorus levels increased significantly in the calcified group, the levels of uric acid(UA), high density lipoprotein cholesterol(HDLC), blood magnesium, and 25-hydroxyvitamin D₃ (25-(OH)-VitD₃) were significantly reduced (P＜0.05); Logistic regression showed that adjusted TC(OR=1.9,5%CI:1.56~2.10), TG(OR=2.3,5%CI:1.86~2.41), HDLC(OR=0.7,5%CI:0.42~0.84), LDLC(OR=2.1,5%CI:1.78~2.32) were still a risk factor for the occurrence of CAC after adjusting for age, diabetes and other factors, and as the levels of TG, TC, and LDLC increased, the levels of HDLC decreased, and their correlation effect values also increased correspondingly (P_trend＜0.05). Compared with the mild calcification group, the age, TG, and TC of the moderate and severe calcification groups significantly increased, HDLC significantly decreased, UA significantly increased in the moderate calcification group, LDLC and blood phosphorus significantly increased in the severe calcification group, while blood magnesium and 25-(OH)-VitD₃ significantly decreased; Compared with the moderate calcification group, the severe calcification group showed a significant increase in TC and LDLC, while UA and HDLC decreased significantly (all P＜0.05). And the multiple Logistic regression model showed that older age, higher levels of TG, TC, LDLC, and lower level of HDLC were independent risk factors for severe CAC in CKD patients after PD treatment (P＜0.05). Restrictive cubic spline regression analysis showed a significant correlation between blood lipid levels and the severity of CAC. ROC curve analysis showed that the AUC of TG, TC, HDLC, and LDLC combined detection was 0.897, with a sensitivity of 0.899, and a specificity of 0.826. This indicated that the predictive value of TG, TC, HDLC, and LDLC combined detection for the severity of CAC in CKD patients undergoing PD treatment was higher than any single indicator. Conclusion The increased levels of TG, TC, LDLC and decreased level of HDLC were significantly associated with the risk of CAC in CKD patients undergoing PD treatment, they were also involved in the occurrence and development of CAC, and their predictive value can be improved through joint examinations in clinical practice.