Objective: To explore the value of echocardiography coronary artery Z-value in the evaluation of coronary artery lesion (CAL) in children with Kawasaki disease (KD). Methods: The data of 85 children with KD complicated with CAL (CAL group, including 52 cases of coronary artery dilatation and 33 cases of coronary artery aneurysm) and 77 children with simple KD (non-CAL group) were retrospectively analyzed. All children completed echocardiography within 24 hours after admission. The Z-values of left main coronary artery (LMCA), right coronary artery (RCA) and left anterior descending artery (LAD) were calculated. Results: In CAL group, the duration of fever, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), procalcitonin (PCT), LMCA-Z value, RCA-Z value and LAD-Z value were higher than those in non-CAL group (P < 0.05). In CAL group, the three Z-values in children with coronary artery aneurysms were all higher than those in children with coronary artery dilatation (P < 0.05). The three Z-values in CAL group were all positively correlated with CRP, ESR and PCT (P < 0.05). Multivariate analysis revealed that the increases of the three Z-values (OR = 2.228, 2.507, 2.737) were all risk factors for CAL in children with KD (P < 0.05). ROC analysis showed that the diagnostic efficacy AUC of the combined diagnosis of the three indicators was 0.903, which was better than the individual evaluation (P < 0.05). Conclusion: The combined evaluation with LMCA-Z value, RCA-Z value and LAD-Z value can effectively improve the diagnostic accuracy of CAL in children with KD.