The occurrence rate of pediatric malignant renal tumors with inferior vena cava thrombus is only 4%‒10%. Tumors extending above the diaphragm (Mayo Clinic level Ⅳ) have the potential to invade the right atrium. Removing the tumor needs a complex surgical cooperative procedure from pediatric, urology, and cardiac surgery doctors, which may cause multiple complications. In this case, a 4‑year‑old patient underwent an intravenous‑inhalation combined anesthesia during surgery. After anesthesia induction, renal artery embolization was performed on the main blood supply vessels of the tumor to reduce intraoperative bleeding. Following the resection of the renal tumor, tumor embolectomy was carried out with the assistance of cardiopulmonary bypass. Intraoperative transesophageal echocardiography was performed to observe the location of the tumor thrombus. Postoperatively, a combination of neural blockade and patient‑controlled intravenous analgesia (PCIA) was administered for pain management. The patient recovered well after surgery. This article discusses the strategies for perioperative management of pediatric patients undergoing cardiopulmonary bypass and postoperative pain management, providing valuable insights for future clinical practice.