We present a case report of peroral endoscopic myotomy (POEM) in the treatment of pediatric patient with achalasia and annular stenosis in lower esophagus. A 9-year-old girl was newly diagnosed with achalasia. After assessment, the patient underwent POEM procedure and the retrievable stent was implanted in the esophagus. Postoperatively, lung CT suggested esophagopleural fistula, while gastroscopy showed that the metal stent was displaced to the esophageal lumen. A fistula was found in the lower esophageal segment after the stent was removed. Emergency operation of endoscopic perforation repair and esophageal stent replacement were performed. The patient recovered well in the next 6 months of follow-up.