Objective To investigate the application and clinical effect of mucosal flap suture combined with T-tube implantation in complex dacryocystorhinostomy. Methods Clinical data of 26 patients (31 eyes) with dacryagogatresia treated with endoscopic mucosal flap suture combined with T-tube implantation from November 2016 to March 2022 were retrospectively analyzed. The surgical methods were summarized and the clinical efficacy was observed. Results The 26 patients (31 eyes) were followed up for 6 to 48 months. The recovery rate was 61.3% (19/31), the significant effective rate was 12.9% (4/31), the effective rate was 9.7% (3/31), the ineffective rate was 16.1% (5/31), and the total effective rate was 83.9% (26/31). Conclusions In difficult dacryocystorhinostomy, nasal endoscopic mucosal flap suture combined with T-tube implantation is less invasive with definite therapeutic effect. Postoperative follow-up should be conducted regularly to improve the curative effect.