Objective To summarize the experience of surgical treatment of late-onset mesh infection after open inguinal hernia tension-free repair. Methods The retrospective descriptive study was conducted. The clinical data of 128 mesh infection patients after open inguinal tension-free hernia who were admitted to the Department of General Surgery of Shaanxi Provincial People’s Hospital form December 2016 to December 2021 were collected. All patients underwent debridement under general anesthesia through a treatment process of laparoscopic exploration, methylene blue staining, removal of mesh, wound irrigation, and negative pressure closed drainage. Patients were observed for completion of surgery, postoperative recovery, and follow-up results. Results One hundred and twenty-eight patients underwent open debridement successfully. In 98 patients, no abnormality was found on laparoscopic exploration and the infected meshs were removed by direct debridement surgery. In 28 patients, laparoscopic exploration revealed that the meshs had broken through the peritoneum and were tightly adherent to the mesentery and intestinal canal. In 2 patients, revealed abdominal abscesses at the paracolic sulcus of the ascending colon and at the ileocecal tract. The infected meshs were removed relatively intact in 112 patients, and the residual meshs were not removed intact in 16 patients. The operative time of 128 patients were 75–345 minutes with an average of 154 minutes, the bleeding volume was 10–200 mL with an average of 37.4 mL, the time to remove the negative pressure drainage tube after surgery were 5–14 days with an average of 8.4 days, the postoperative hospital stay were 6–18 days with an average of 11.6 days. There were 114 cases of class A healing, 12 cases of class B healing, and 2 cases of class C healing. One hundred and twenty-eight patients underwent postoperative follow-up for 6 to 60 months, with a media follow-up time of 30 months. During the follow-up period, 4 patients developed ipsilateral inguinal hernia recurrence, 4 patients developed reinfection, and 3 patients developed varying degrees of pain in the inguinal region. Conclusions Late-onset mesh infection after open inguinal tension-free hernia repair requires removal mesh by surgical treatment. Laparoscopic exploration, methylene blue-assisted debridement, complete removal of the mesh, strict wound irrigation and negative pressure closure drainage are safe and reliable treatment.