Postthrombotic syndrome (PTS) is one of the long-term sequelae of deep vein thrombosis (DVT), and effective symptom management in pediatric PTS remains a challenge, with interventional therapy rarely explored in this population. We present a successful case of interventional treatment pediatric PTS, resulting in a remarkable amelioration of her symptoms. This case features a 6-year-old girl diagnosed with hyperinsulinemia, leading to a hypoglycemic coma. Following a mini-pancreatic partial pancreatectomy, she required further intensive care in the pediatric intensive care unit. It was during this period that left lower extremity DVT was identified, prompting warfarin anticoagulation therapy. During the anticoagulation period, she had several bleeding events and was switched to anticoagulation with low molecular heparin. One month later, the left common iliac vein and external iliac vein was found to be completely occluded. Over time, she experienced a gradual onset of lower limb swelling and pain, which, after 6 months, was accompanied by perineal edema and venous claudication. As a result, she underwent successful percutaneous transluminal angioplasty. In addition, the anticoagulation regimen was adjusted to rivaroxaban. At the 8-month follow-up, we observed significantly improvement in her postoperative lower extremity swelling and symptoms related to venous occlusion had completely disappeared. Moreover, vascular imaging confirmed improvement in stenosis and uninterrupted blood flow. In our review of pediatric PTS studies, we observed limited options to alleviate symptoms, and interventional treatments have not been reported. Our case study, demonstrating the safe and effective use of percutaneous transluminal angioplasty, helps to illuminate this area and alleviate pediatric PTS symptoms. This case validates the efficacy and safety of using percutaneous transluminal angioplasty (PTA) for the treatment of postthrombotic syndrome (PTS) in pediatric patients. This interventional approach offers significant symptomatic relief and improves quality of life, especially in cases where traditional anticoagulation therapies fail or lead to complications. The successful case presented emphasizes the necessity of considering endovascular interventions for children with moderate to severe PTS, particularly when conservative management is ineffective. This research underscores the potential for PTA to be adopted in clinical practice, offering a promising new approach for managing pediatric PTS.