【Abstract】Objective To explore an effective method ,improve the accuracy of diagnosis of inguinal hernia in children in order and provide reliable technical support for clinical treatment. Methods In supine position and standing position, High frequency ultrasound was used to probe inguinal hernia, determine the site, observe the shape, trend, the relationship with the scrotum and the relationship between the scrotum and the abdominal wall. Results 148 patients of inguinal hernia diagnosed by B ultrasound were confirmed by operation. The diagnostic rate was 100 %. 5 cases were unilateral hernia, which were confirmed by B ultrasound and operation. In 148 cases of inguinal hernia, only 1 case was misdiagnosed as femoral hernia. The accuracy rate of classification was 99.32%. Of 125 cases of indirect hernia, 99 cases could be detected pear shaped or long strip mass. 61 cases (61.62 % ) hernia contents were bowel and 38 cases (38.38 % ) hernia were clathria membrane. The intestinal contents of 15 cases were bowel. The contents of 8 cases were clathria. 15 children with direct hernia could get the spherical mass of the intestinal canal in the supine position in the supine position. 8 patients with femoral hernia in the supine position could enter the greater omental sac from the inner side of the femoral vein. In children with 2080 hernia, the contents of hernia in prostration and quiet breathing were in the abdominal cavity completely. The inner collar extension could enter the inguinal canal through the valsalva action. The sensitivity, specificity and accuracy of Bultrasound examination were significantly better than that of the surgical examination (P＜0.05). Conclusion High frequency ultrasound not only can make more accurate diagnosis of inguinal hernia, but also clear the type of inguinal hernia, and distinguish the content of inguinal hernia, which can be used as the first choice of imaging examination of inguinal hernia. Valsalva action can help the diagnosis of atypical inguinal hernia.