Objective To evaluate the safety and reliability of a novel technique of single-port laparoscopic-assisted percutaneous precise closure of the inguinal hernia sac in children. Methods From September 2016 through September 2019, children with inguinal hernia(s) treated with single-port laparoscopic-assisted percutaneous extraperitoneal closure using a guide wire were enrolled in this study. Operative time, surgical complications, recurrence rate, and cosmetic results were collected. Results A total of 917 cases with inguinal hernia(s) were collected. Among them, there were 886 (96.61%) boys and 31 girls. Their mean age was 5.2 ± 3.7 years. There were 693 (75.57%) cases with unilateral hernia. There were 224 cases with bilateral hernias or patent processus vaginalis, including 135 (14.72%) cases with an open contralateral ring which was confirmed intraoperatively. Twenty-three (2.51%) needed another port to complete the hernia sac separation. The operation time was 24.7 ± 5.2 min and 14.6 ± 3.8 min in bilateral and unilateral ones. Three cases complained of numbness in the thigh region or groin pain which subsided without medication in the 2nd postoperative month. There was no recurrence, and the incision scars were nearly invisible. Conclusion Single-port laparoscopic-assisted percutaneous extraperitoneal closure using a guide wire is a safe, less cost, and reliable technique in the treatment of inguinal hernia in children.