Objective To investigate the application and clinical efficacy of orthotopic autologous renal transplantation combined with inferior vena cava (IVC) resection and reconstruction in retroperitoneal tumor. Methods The clinical data of a patient with complex retroperitoneal tumor was analyzed retrospectively. Abdominal CT examination showed that the tumor originated from IVC and invaded the retrohepatic IVC and bilateral renal vein trunks. Intraoperative ultrasound exploration revealed mechanized thrombosis in the IVC and bilateral renal vein trunks. After blocking the left renal vein, no significant hemodynamic changes were seen before and after intraoperative ultrasound exploration and contrast-enhanced ultrasound. Results After complete removal of the left renal vein and suture of the severed end, the right renal vein was successfully reconstructed with an orthotopic autologous right kidney graft combined with IVC resection after removal of the mechanized thrombus. The patient recovered well after surgery, and a repeat CT showed that the reconstructed artificial IVC was patent, and the color Doppler ultrasonography of both kidneys showed good perfusion and no obstruction of return. The patient was given oral rivaroxaban anticoagulant therapy after operation, and discharged at 19 days after operation. The postoperative pathological findings suggested inferior vena cava smooth muscle sarcoma. Conclusion Orthotopic autologous renal transplantation combined with IVC resection and reconstruction for complex retroperitoneal tumor is safe and feasible, and the left renal vein can be ligated and dissected intraoperatively, but a comprehensive evaluation with intraoperative ultrasound (imaging) is required.