Background: Secukinumab, an IL-17A inhibitor, is approved for moderate to severe psoriasis in children over 6 years old in the European Union and the United States, but not yet in China. This study evaluates the clinical efficacy and safety of secukinumab in Chinese pediatric patients with moderate to severe plaque psoriasis. Methods: A randomized, single-center study was conducted with 33 patients aged 6 to 17 years. Patients were treated with either secukinumab or conventional non-biologic therapy. The primary outcomes assessed included body surface area (BSA), Psoriasis Area and Severity Index (PASI) 75/90/100 responses, Investigator’s Global Assessment 0/1 (IGA 0/1), Dermatology Life Quality Index, and the incidence of adverse events (AEs). Results: Compared to the conventional treatment group, the secukinumab group demonstrated significant reductions in BSA and PASI scores, as well as higher rates of IGA 0/1, Dermatology Life Quality Index improvement, and PASI 90 response. Subgroup analysis of the secukinumab group indicated lower BSA and PASI scores in patients without prior treatment compared to those with prior treatment. No significant differences were observed between the 150 mg and 300 mg dose groups regarding BSA and PASI decrease rates. Conclusion: Secukinumab demonstrates therapeutic efficacy and safety in the treatment of moderate to severe plaque psoriasis in pediatric and adolescent patients, suggesting its potential as a treatment option for this population.