Background: In treating juvenile-onset laryngeal papillomatosis, the most difficult aspect is preventing recurrence. After a single treatment, recurrence can begin after as soon as 20 days and the recurrent rate can be higher than 90%. The causes of recurrence include the presence of mucosal cells infected with papilloma virus, which are undetectable with the naked eyes, and surgery-induced infection. Photodynamic therapy (PDT) could effectively solve this problem. Virus-infected cells have a very high metabolic energy for capturing and internalizing the photosensitizer, which, after light stimulation, subsequently induces active oxygen species inside the nucleus, which kill infected cells. The second generation of photosensitizer agents (PA) are locally applied to avoid the intravenous systemic damage caused by first-generation PAs, and this method is widely used for the treatment of genital warts to very good effect. Methods: We used the photodynamic method to treat laryngeal papillomatosis in children and obtained significant efficacy. We followed three juvenile subjects with recurrent laryngeal papillomatosis through a course of treatment (each course includes three PDT sessions), with a follow-up after 6 months. Results: The characteristic procedures involve exposing the larynx with a laryngoscope and using low-temperature plasma technology to visualize the tumor resection, as the effects of plasma technology can reduce postoperative laryngeal edema and reduce intraoperative metastasis. PDT was performed during the first surgery, 20 days after and 30 days after surgery. At the 6-month follow-ups, there was no recurrence. Conclusion: This was the world's first successful reported case of the use of PDT treatment for juvenile laryngeal papillomatosis.