Objective. To investigate the correlation between carotid intima-media thickness (IMT), ankle-brachial index (ABI), and coronary artery dilatation (CAD) in children with Kawasaki disease (KD) and to evaluate the effectiveness of CAD. Methods. A total of 68 children diagnosed with KD from January 2019 to January 2021 in our hospital were included. According to the results of cardiac color Doppler ultrasound, the children with KD were divided into a noncoronary artery dilation group (NCAD), with 41 children with KD who did not have coronary artery lesions, and a coronary artery dilation group (CAD), with 27 children with KD who had coronary artery dilation. 27 healthy children undergoing physical examination in our hospital at the same time were selected as the normal control group. Laboratory index of all subjects was measured individually. The carotid IMT, ABI, and coronary artery diameter of all subjects were measured and compared. Pearson correlation was used to analyze the correlation between carotid IMT, ABI, and the severity of coronary artery disease. The ROC curve was used to evaluate the efficacy of carotid IMT and ABI in predicting coronary artery disease. Results. The ALB of children in the CAD group was lower than that in the NCAD group P < 0.05 . The IMT of carotid artery and the diameter of coronary artery in children of the CAD group and the NCAD group were higher than those of the normal control group, and the IMT of the CAD group was higher than that of the NCAD group. The ABI of children in the CAD group and the NCAD group was lower than that of the normal control group, and the ABI of children in the CAD group was lower than that of the NCAD group P < 0.05 . Correlation analysis showed that carotid artery IMT of children with KD was positively correlated with coronary artery diameter, while ABI was negatively correlated with coronary artery diameter. The AUC of carotid IMT for CAD in children with KD was 0.668 (95% CI: 0.538–0.797), that of ABI for CAD in children with KD was 0.646 (95% CI: 0.513–0.780), and that of the combination of carotid IMT and ABI for CAD was 0.874 (95% CI: 0.785–0.963). Conclusion. The changes of carotid artery IMT and ABI in children with KD have a certain correlation with CAD, and the joint detection of carotid artery IMT and ABI can provide clinical reference value for predicting the degree of coronary artery disease in children with KD.