Objective To investigate the clinical characteristics, genetic profiles, and therapeutic outcomes of oxcarbazepine in children with congenital myotonia (MC). Methods A retrospective analysis was conducted on three pediatric MC cases, summarizing their clinical manifestations and treatment courses. All patients underwent next-generation sequencing (NGS) for genetic diagnosis. Results All three cases initially presented with movement disorders and were misdiagnosed as paroxysmal kinesigenic dyskinesia (PKD). Genetic testing revealed pathogenic variants in the CLCN1 gene, confirming MC diagnosis. Remarkably, all patients achieved symptomatic relief after oxcarbazepine administration. Conclusions MC patients exhibit diverse clinical features, including the "warm-up phenomenon," positive family history, and specific genotypes. While medications such as mexiletine and acetazolamide are effective, individualized treatment strategies are essential. Early diagnosis and proper intervention are crucial for improving patients' quality of life and prognosis. This study preliminary report the efficacy of oxcarbazepine in MC treatment, providing valuable insights for clinical practice.