Objective To investigate the value of ultrasonography in differentiating umbilical polyps from umbilical granuloma in children. Methods The clinical and ultrasonographic data of 24 children with umbilical polyps (umbilical polyps group) and 40 patients with umbilical granuloma (umbilical granuloma group) who were pathologically diagnosed in our hospital and Wuxi Children's Hospital from July 2013 to May 2021 were collected, the differences in ultrasonographic characteristics between the two groups were compared and analyzed, the diagnostic odds ratio (OR) of various ultrasonographic findings was weighted to establish a combined diagnostic equation, and ROC curve was used to assess the differential diagnostic efficacy.Results There were significant differences in age and sex between patients with umbilical polyp and umbilical granuloma (P < 0.05). Univariate analysis showed that there were significant differences in the ultrasonographic characteristics of the umbilical polyp umbilical granuloma group in terms of lesion depth, lesion and sinus tract below the umbilicus (P < 0.05), and the differential diagnostic efficacy was expressed as AUC: deep lesion depth: 0.694 (95% CI: 0.560 to 0.829); poor or absent lesion: 0.762 (95% CI: 0.635 to 0.889) and the presence of sinus tract below the umbilicus: 0.699 (95% CI: 0.556 to 0.843). Multivariate analysis showed that the regression coefficients obtained in terms of lesion depth, lesion and sinus tract below the umbilicus were statistically significant. Using the combined diagnostic equation of comprehensive multiple factors, the AUC under ROC curve was 0.873 (95% CI: 0.769 ~ 0.977, P = 0.001), the sensitivity and specificity of differential diagnosis of umbilical polyps were 84.6% (95% CI: 67.5% ~ 93.0%) and 87.2% (95% CI: 78.6% ~ 95.2%), respectively, and the differential diagnostic efficacy was superior to that of single factor (P = 0.018, 0.038, 0.002).Conclusion The ultrasonographic features of umbilical polyps and umbilical granulomas in children have certain specificity, and the combined diagnosis can further improve the efficacy of differential diagnosis.